Commitment of the Maintenance Personnel. Verification of Implementation Metrics and Process Improvement 1.5 Dynamics of a Maintenance Organisation Maintenance Management Perspectives Types of Maintenance Preventive Maintenance Shut-down Maintenance Opportunistic Maintenance 1.6 Summary 1.7 Terminal Questions 1.8 Answers 1.1 Introduction Rising inflation and increased competition have brought with them the need for greater productivity, and recent years have seen more emphasis being placed on productivity improvement. Moreover, sophisticated equipment and capital intensive units and plants are being increasingly used to achieve the pre-set targets of higher production and productivity. Reliability and maintainability features are now being incorporated in the equipment designs. Although modern equipment has higher levels of reliability, it is not possible to keep this equipment in an operating condition at all times because failures do occur even in the most reliable equipment.1 It is also true that such sophisticated equipment, and units or plants, tend to have high probabilities of failure since in many cases they incorporate newer, and therefore not adequately proven, technologies and designs. They also consist of a large number of assemblies, sub-assemblies and components. Failure and malfunctioning of these items of equipment result in a loss of production. Loss of production is undesirable because it results in corresponding loss in revenue. Whenever an item of equipment is down and fails to perform its intended function, or performs in an undesirable fashion, it must be restored to a state where it performs satisfactorily. At the same time all necessary action must be taken to keep, or retain, such equipment in an operating condition and also to prevent failures. Resources, such as spare parts, manpower skills, tools, instruments and facilities, such as hangars in the case of

aircraft maintenance, are utilized for accomplishment of the restoration processes and preventive actions. Thus the requirement for productivity improvement has brought about the pressing need for a significant improvement in the management of maintenance of equipment, units and plants. Objectives: After studying this unit you shall be able · To Define Maintenance · To assess objective and functions of Maintenance · To describe Quality aspect of Maintenance · To assess key process of Maintenance Management 1.2 History of Maintenance Historically, maintenance activities have been regarded as a necessary evil by the various management functions in an organisation. Enormous costs of maintenance, estimated to be between 15 and 40 per cent of the production costs and the trend towards automation have, however, forced managers to pay more attention to maintenance. The evolution of maintenance can be traced from the days prior to World War II. The attitude of the managers then was ‘to fix the equipment when it breaks’. With fewer items of sophisticated equipment around, and hence, the cost of downtime not being high, prevention of equipment failures was not given much attention. Maintenance, in addition to fixing the broken equipment, involved simple activities like cleaning and lubrication. The period after World War II saw the introduction of the word ‘terotechnology’ which was initially defined by the committee on terotechnology as ‘…a combination of management, financial, engineering and other practices applied to physical assets in pursuit of economic life-cycle costs’. Due to rising costs and inflation, focus was on reducing downtime of equipment and hence preventive maintenance came into being as an important activity. This period also saw a number of researchers working on operations research models for preventive maintenance. Importance of planning maintenance activities also grew during this period. Overhauls of equipment were planned and scheduled. Systems for managing maintenance were also introduced. The period after 1980 has seen some of the worst accidents in industrial history. Leakage of methyl isocyanite (MIC) from a battery/cell manufacturing unit in Bhopal in India and the threat to the survival of mankind caused by the nuclear accident at Chernobyl in the erstwhile Soviet Union have only made the manufacturing industries and the like realize the importance of maintenance. The attitude of ignorance towards maintenance has increasingly been replaced by one which recognizes maintenance also as a strategic issue in the organisation. Besides high cost, the other factors which contributed to this change

Alternatively the objective should be to minimize the costs – the labour costs and the material costs as well as the loss in revenue due to loss of production. drive for cost reduction and the like. should. In case an item of equipment fails it needs to be restored to the same specified operating condition. maintenance activities which do not contribute to preserving or restoring the intended functions of assets should be eliminated. or restoring failed equipment to a normal operating condition. · To extend the useful life of the equipment. Obviously. in general. be to maximize the profitability of the organisation by performing activities which retain working equipment in an acceptable condition. 1. which is linked to the overall organizational objectives. The objective of maintenance. Performing such activities would obviously extend the useful life of the equipment. In summary. an item of equipment in a specified operating condition. safety issues. and planning and scheduling maintenance resources.2. Modern maintenance management can be considered to be composed of the following functions: · maintenance planning. Maintenance. and warranty and liability factors.include: environmental concerns. means preserving.
. The availability and utilization of these resources are of prime importance.1 Definition of Maintenance Maintenance is an element of a complete production system. neural networks and Markov chains have been used for controlling and managing maintenance activities. or return the equipment to an acceptable working condition. To live up to the new expectations demanded of maintenance activities. at minimum resource cost. manpower. · organizing maintenance resources. regulatory matters. ageing plant and equipment. The set of tasks or activities that constitute maintenance ranges from simple cleaning operations and lubrication to performing condition monitoring. the principal objectives of maintenance would be: · to control the availability of the equipment. Techniques such as condition monitoring. including staffing/recruiting. or keeping. that are related to preserving equipment in a specified operating condition. 1. maintenance programmes have to be developed to ensure that physical assets will continue to fulfill their intended functions at a minimum expenditure of resources. or tasks. The need for reliable equipment has also been realized.2 Objectives and Functions of Maintenance The objective of any business organisation is to make profits. Maintenance can thus be defined as a set of activities. tools and facilities. therefore.2. Performing maintenance activities requires the use of resources such as spare parts.

. 5. 3. involved simple activities like cleaning and lubrication. _____________ in addition to fixing the broken equipment. The attitude of ______________ towards maintenance has increasingly been replaced by one which recognizes maintenance. Maintenance planning includes formulating and identifying ___________ policies. · defining processes for performing maintenance.· directing execution of maintenance plan. Maintenance planning includes formulating and identifying organisation-wide policies that would help achieve higher maintenance productivity such as: · Do we repair the equipment or buy a new one? · Do we perform preventive maintenance or corrective maintenance activities? · Do we employ full-time repair personnel or should we subcontract work?
Self Assessment Questions 1. The principal objectives of maintenance would be to control the availability of the equipment. · Budgeting. 2. Maintenance is an element of a complete ___________ system. at minimum ________________. 4. · controlling the performance of maintenance activities.

the maintenance manager needs to organize the required resources and all these resources need to be available in the right quantity and at the right time. Once the activity is complete. Other common tasks related to maintenance management include generating reports related to equipment. a review by the manager or the maintenance supervisor would be essential to ensure and authorize that the maintenance work has been carried out properly. This will lead to degradation of equipment performance and can also result in its failure. then the planned maintenance activity cannot be performed. This way not only is the downtime cost kept to the minimum but also the resources are utilized effectively.1. Once the required resources are available.3 Functions of Maintenance Management Responsibility for formulating the maintenance policies lies with top management. This is a statement of maintenance tasks to be carried out in a specified period. work and
. Another important task is creation of a master maintenance schedule. In order to carry out maintenance activities as planned. Any maintenance activity requires resources. In case the task does not get completed within the estimated time then corrective action would need to be taken to ensure further loss in revenue due to loss in production is minimized. the maintenance activity can be initiated. The maintenance manager should track the work to completion. The top management is also responsible for negotiating and authorizing the service level agreement. If the required resources are not available. The maintenance manager should ensure that the equipment is restored to its normal working condition as quickly as possible.

It also includes activities related to collection and analysis of data related to maintenance and reporting to top management. · It incurs not more than the budgeted cost. · an appropriate ‘on-the-job’ training programme for the repair men to enhance their ability to work. · A repository of maintenance processes.2 Maintenance Organisation Maintenance organisation does not mean only the organisation of people in the maintenance department or their reporting structure. A ‘process’ can be defined as a set of tasks that. · it is initiated on time and the equipment is returned to production at the · required time. when performed properly. It is more to do with the maturity of the maintenance process such that high-quality maintenance activities are performed. the need is for a good maintenance organisation.3. · the required spare parts in the required quantity.1 Quality Aspects in Maintenance Quality is not absolute but relative. A maintenance activity can be considered to be of high quality if: · it restores an item of equipment to its normal working state. produces the desired result. An effective maintenance process must consider the relationships of all the tasks. The above-mentioned conditions can be satisfied only when the maintenance organisation has: · skilled and committed repair men available to carry out the required maintenance activity at the required time. 1.costs. instruments and facilities for performing the activity. · the required tools. · In general. and the skill. 1. measured and improved. the tools and procedures used. training and motivation of the people
.3. without causing · any damage to the equipment or to any of its parts. An important step in addressing the maintenance management problems is to treat the maintenance task as a process that can be controlled.

1. 1. 3. The organisation now has capabilities to face new challenges and achieve success. organizations must have dedicated personnel who take care of the development processes. repeatable. Plan to perform the required actions. The performance of these steps calls for a process-oriented organisation and such an organisation develops over a period of time as enunciated by the capability maturity model (CMM).6 Managed Level
. the most important ones being project management.3 Initial Level The organisation operates on an ad hoc basis. 4. In order to improve performance.3. organizations at this level face risks when presented with new challenges.*9 The CMM was defined by the software engineering institute (SEI) for software development organizations and it classifies software development organizations into five levels initial. List down required process improvement actions.5 Defined Level The organisation has a repository or a set of defined procedures for carrying out development work. To improve the capabilities of the maintenance organisation the following steps8 must be performed consistently: 1. organizations at this level need to institutionalize basic management processes. managed and optimized. 1. defined.3. Determine if the current process is the desired process. that is. To climb up the maturity level. 5.3. The strength to carry out similar activities stems from the prior experience. Commit resources to execute the plan. With this. cost estimates and plans.4 Repeatable Level Organizations which carry out similar projects with reasonable accuracy with regard to cost and time are at this level. 1. the organisation has to implement a measurement programme to obtain process feedback. However. without formalized procedures. quality assurance and project tracking and oversight. Understand the status of the current maintenance process or processes.3.involved. the organisation achieves the foundation for continuous improvement in processes. Tools are neither integrated with the process nor uniformly applied. To reach the defined level. 2.

Quality is not absolute but relative. The objective is only to identify the key process areas that would enable maintenance organizations to enhance their capabilities and maturity. the organisation needs to put in place automatic data collection support tools. without formalized procedures.The organisation has a way by which performance indicators are measured objectively. Self Assessment Questions State whether following statement True or False 6. 7. A ‘process’ can be defined as a set of tasks that. 1.
. · quality assurance. To reach the highest level on the CMM. that is. 8. Responsibility for formulating the maintenance policies lies with shop Supervisors. The CMM can be adapted to enhance the capabilities of the maintenance organizations as well. A few key process areas can be readily identified in this regard. cost estimates and plans. produces the undesired result. Since the data collection process is full-fledged. 10. Problems are identified proactively and eliminated. Any maintenance activity requires resources. The objective is not to classify the maintenance organizations also into one of these levels. Targets are set for performance and a plan is made out to achieve the pre-set targets. 1. · resources management. · supervisory review. when performed properly. the effectiveness of the process can also be determined. 9.4 Improving Maturity in Maintenance Organizations The key process areas (KPAs) involved in enhancing the capability and maturity of a software organisation. The organisation operates on an ad hoc basis.3. They are: · training strategy. · work management.7 Optimized Level The organisation has capabilities to identify the weakest links in the development processes and eliminate/improve them.

1. maintenance activities require resources in the form of spare parts. a small maintenance activity may take not less than 5 hours. The required resources should be available at the right time and in the right quantity. tools. In some others. Each of the tasks in the work-breakdown structure should have appropriate resources assigned to it. The supervisor’s responsibility is to ensure that the required resources allotted for performing
. Individual as well as organisation-wide training programmes should be planned. Management of resources is therefore critical to managing the maintenance function. The term ‘small activity’ should be defined by the quality assurance personnel because it varies from one organisation to another. Also the probable time to complete the tasks should be specified. For example. Coordination within a group is critical to completion of the maintenance task on time. in one organisation an activity that takes only 15 minutes for completion is considered to be small.4. Every maintenance activity should be planned.1 Training Strategy Every maintenance organisation should have a suitable training programme for its personnel. instruments and facilities. It therefore becomes necessary to train all the maintenance personnel on the aspects of team work. This is referred to as the work-breakdown structure. manpower. scheduled and tracked to completion. tools. A maintenance activity should be broken down into smaller manageable tasks. a bull’s eye chart may be appropriate for tracking work. such as an oil refinery. 1.4.2 Work Management Any activity. Resource here means manpower. Training. facilities etc. 1. a welder may be re-trained to perform a pipefitter’s job. 1. In such a case it is better if some of the available personnel are re-trained on some trades other than those in which they have specialized.3 Resources Management As mentioned earlier. for example. An organisation may not always find suitable people for performing a job. Holding resources in excess of requirements is wasteful while non-availability of required resources at the required time is undesirable since this result in loss of revenue due to loss in production. Most maintenance activities are performed in groups. is not managed if it is not planned and tracked. For example.4.· Subcontract management. usage of modern tools etc.4. irrespective of the time it consumes. This is the responsibility of the maintenance manager. scheduled and conducted. The maintenance manager should identify the training needs of his subordinates and get them trained. For small activities. It would not be appropriate to track every small activity in the work-breakdown structure to completion.4 Supervisory Review Every maintenance activity should be performed under the charge of a supervisor. can be provided on safety and productivity-related issues.

is expensive. This is the work order management process.6 Subcontract Management A few maintenance activities require specialists at the job. This involves establishment of policies and top management sponsorship. List of activities. in most cases. The goals of the subcontract management should be to evaluate and select appropriate subcontractors for performing the maintenance activities. The maintenance manager can also visit premises to inspect the capabilities and to get firsthand information. Increasing the ability to perform. The supervisor should also report completion of the activity to the maintenance manager so that the actual costs incurred are logged. Ability of the maintenance personnel can be enhanced by providing them with proper and relevant training. Hiring these specialists on a full-time basis. The subcontractor manager should select a suitable subcontractor based on a balanced assessment of the capabilities of prospective subcontractors. Once the activity is complete.4. and for analyzing them in order to come up with improved routes and work processes. tools etc. 1. subcontracted work should also be managed. 1. the supervisor should inspect the equipment in order to ensure that the equipment is performing as desired. Yet another goal would be to verify the correctness of the work performed.the maintenance activity are available to the repair gang on time and in the required numbers.5 Quality Assurance The quality assurance personnel should be responsible for identifying the optimum route for performing a maintenance activity. The selection of the subcontractor should be planned.4. The repair men should be provided with a list of activities that need to be performed as a part of the maintenance. 1. The supervisor should also guide the repair gang in performing the activity. Like any other internal maintenance activity. They are responsible for collecting data while the maintenance activity is carried out. 1. A few more basic areas like maintenance planning and configuration management would also need to be considered.4. These factors have also been borrowed from the CMM. A better option is to subcontract the work.4. Five important factors need to be taken care of if each of the key process areas mentioned above need to be implemented in the maintenance organisation.8 Verification of Implementation
. The assessment of the subcontractor can be done by inviting each to present their capabilities and verification of claims through independent references.7 Commitment of the Maintenance Personnel The repair men need to be committed to perform the maintenance activities.

estimated time to complete the work. Gathering metrics on every maintenance activity helps in estimating the time requirements and also the cost. 15. 13.5 Dynamics of a Maintenance Organisation Coordination within the groups is one of the most important factors that determine the effectiveness of any maintenance organisation. The key process areas (KPAs) involved in enhancing the capability and maturity of a ____________________. 4. 14. Ability of the __________________ can be enhanced by providing them with proper and relevant training. They are as follows: 1.9 Metrics and Process Improvement This is a continuous process. 12. An activity is scheduled (as far as possible during the production windows in the case of preventive maintenance) and initiated depending on the availability of the required
. tools etc. The supervisor should also make use of this opportunity to identify the strengths and weaknesses of the individual repair men and arrange suitable training for them. The maintenance manager is responsible for scheduling maintenance activities. Four entities are important as far as the maintenance activities are concerned. The supervisor group. 1. 1. Every maintenance organisation should have a suitable ___________ for its personnel. 3. Feedback on the maintenance activity performed should be given to the concerned repair men.The supervisor of the repair men should verify the completion/ implementation of the maintenance activity. The resources. 2. Self Assessment Questions 11. materials and tools. The selection of the ______________should be planned. including manpower.4. The quality assurance group. the maintenance productivity and quality of the maintenance work. The maintenance manager. Measurement of maintenance activity can be in terms of percentage of work complete to date. Metrics and process improvement is a ___________________.

The maintenance manager tracks the activity to completion while the supervisor inspects and ensures the activity is carried out properly. 2. They have divided corrective maintenance into two perspectives – ‘reactive’ and ‘reactive/proactive’ –and have defined preventive maintenance as a ‘proactive’ perspective. The equipment is in a failed condition. Since the equipment is being taken out of production this maintenance activity results in loss of production. The quality assurance group determines the process of performing the maintenance activity in an optimized manner. Since the equipment is not in an operating condition this maintenance activity results in considerable loss of production. The equipment is not wanted for production and is available for maintenance. The key distinction among the three perspectives relates to the time interval between the recognition of the need to perform a maintenance activity and the time at which the
. Relatively more time is spent on performing this type of maintenance activity. Since the equipment is in use there is no loss in production while performing this maintenance activity. It can be seen from the above that there are two perspectives of maintenance management: 1. 4.5.resources. This is called the ‘production window’. The equipment is taken out of production for a scheduled maintenance activity. Maintenance is carried out while the equipment is running. this is called corrective maintenance. (2) and (3). The equipment is in a failed condition. Due to shortage of resources the maintenance activity is pending.1 Maintenance Management Perspectives Kelly has described the dynamics of a production maintenance system considering a large process plant. The equipment is running and is producing the desired output. the quality assurance group collects data on the process and analyses them with a view to improving the process. Prevent it from breaking down as in cases (1). Ettkin and Jahnig have described the work life cycle for the reactive and proactive perspectives. 2. 1. this is called preventive maintenance. an item of equipment or some part of it can be in one of the five following states: 1. Fix it when it breaks as in cases (4) and (5). As the maintenance activity is carried out. This activity involves simple inspection of replaceable parts. Maintenance is being carried out to restore the equipment to an operable condition. 3. 5. This maintenance activity also does not incur any loss in production. At any time.

The cost of utilization of these resources is a direct maintenance cost. materials and tools. corrective and other maintenance practices followed in organizations. The following section describes the preventive. As the level of performing maintenance activity increases. consisting of labour costs.2 Types of Maintenance The return of investment on an item of equipment can be maximized by maximizing its availability. the direct costs increase. Availability of an item of equipment can be defined as the ratio of uptime to the sum of uptime and downtime. 1. The cost of unavailability. In the case of the ‘reactive’ perspective. When an item of equipment is down it results in loss of production which. This approach to maintenance becomes essential for any equipment where there are serious dangers to life should a failure occur. Just as there is a trade-off between inventory holding costs and the reordering costs. The total maintenance cost is the sum of direct maintenance costs.activity is actually performed.3 Preventive Maintenance Preventive maintenance is a proactive activity. v Evaluation of the performance. for example. in the case of nuclear submarines. There is rarely any organisation where only one type of maintenance is used. The intention is to detect potential failures early. and indirect maintenance costs.5. Most situations warrant a considerable mixture of maintenance types. If personnel who operate and maintain the nuclear power plant of the submarine make serious mistakes. The only difference is that of the time interval. v scheduling the maintenance task. make changes and prevent failures. the time interval between the recognition and performance is very small as compared to the ‘proactive’ perspective. All the maintenance activities. The level of maintenance activity to be performed is obviously the one where the total cost is minimal. The preventive actions under such a situation would be to:
. in turn. 1. This is an approach developed to reduce the likelihood of the failure of critical equipment to the minimum possible. there is a trade-off between the maintenance costs and their benefits. Also the indirect costs resulting due to failure decrease. which is an indirect cost. the ship and its entire crew are in mortal danger. Performing a maintenance activity requires usage of resources such as manpower. v performing the maintenance task. involve the following steps: v planning the maintenance task.5. is proportional to the loss in revenue. which are primarily due to loss of production. regardless of the maintenance perspectives. material costs and direct overheads. results in loss of revenue.

These activities can prevent serious errors from occurring.. the level of distilled water in the battery of an automobile is checked after every 1000 kilometers and the brush ploughs of a grinding mill should be replaced after every 500 hours of running. · servicing. · Audit the personnel so that they demonstrate satisfactory performance to their job standards. Fixed-time maintenance is that activity which involves inspection of critical parts of the equipment after a fixed time interval. power plants etc. Primary objectives of this approach to maintenance are to: · Increase the life of critical equipment by preventing failures.· Train all the personnel in their own jobs. This approach to maintenance is also important in highly automated plants. · Report deviations to the admiral-in-charge. which includes lubrication. where the cost due to loss in production is very high. · Detect the onset of a failure. · Inspect each ship and each operation to ensure that every procedure and method is properly understood and executed. · Replacement of worn-out parts. or after generation of a fixed cumulative output. and replacement of those which are worn out. hours etc. The fixed time should not be based on the calendar units but should be based on a fixed number of running units such as kilometers. Planned · activities are carried out and the main functions are: · inspection of critical parts of the equipment. and the commanding officer must promptly report on the corrective actions. · Condition-based maintenance. This type of maintenance activity is applicable only for those items which exhibit a time-dependent failure
. Analyze even the most trivial errors to determine what went wrong. For example. adjustment and similar activities. These objectives give rise to the following methods of performing preventive · maintenance activities: · fixed-time maintenance. such as car assembly.

The costs involved in condition monitoring may vary widely.mechanism. the maintenance-related costs are usually high for the following reasons: The time required is usually much higher than other maintenance types because the cause of failure has to be identified. In organizations where there are very few production windows. such as the setting of warning limits for the Solidification of the lubricant. This is a proactive-reactive approach to maintenance and results in the following tasks: repair of failed parts of the equipment. as mentioned earlier. ultrasonic waves and thermographs also help monitor the condition of the equipment. and then the parts have to be repaired or replaced. which can be measured either visually or by other means. checking for leaks in fuel-carrying pipes. The obvious advantage of carrying out running maintenance is that there is no loss in production. This approach is designed to detect the onset of a failure. analysis of acoustic emissions. This method of condition-based maintenance is inexpensive. cracks in the structure of a building etc. For example. There is a cost due to loss in production. Corrective Maintenance Corrective maintenance. correlating to the onset of failure has been identified. Complex situations require sensors and other high-tech tools to monitor the vibrations. or how the failure can be prevented is not yet known. replacement of failed parts with new ones. A parameter. Although. Condition-based maintenance is also known as predictive maintenance. Running maintenance is normally carried out in situations where there is no threat to the life of the maintenance personnel. which the case is when the event leading to failure occurs in a predominantly random manner. is a reactive activity and is performed when an item of equipment is not in an operating condition or is operating at a level below its rated capacity. Techniques such as oil analysis. generally occurring in the form of breakdown maintenance. the maintenance personnel can also collect data which can be used as inputs by other methods of condition-based maintenance procedures. A simple case of condition-based maintenance is the visual examination of the brake pads of an automobile. This type of maintenance is called running maintenance. eddy currents. These methods. on the other hand. It is an appropriate option for preventive maintenance when the following conditions apply: Prevention of failure is not technically feasible. Damage is caused to other equipment as a consequence of failure. if repair is not economical. Detailed analysis helps in detecting an impending failure. It is possible to identify a value of that parameter when action may be taken before full failure occurs. With this kind of maintenance policy. In some situations it is possible to carry out some preventive maintenance activities while the equipment or plant is running. corrective maintenance is predominant. the time required to perform this activity is
. Corrective maintenance activities are also performed when condition monitoring indicates onset of a failure. Along with inspection. are expensive. Since condition monitoring gives sufficient warning of an impending failure it becomes easy for the maintenance manager to plan a corrective activity at a later time. shock pulses etc. the solidification of the lubricant is an indicator of the machine’s wearing condition.

Trained maintenance personnel also have a role to play in reducing the maintenance time. 1. 17. as well as major repairs and overhauls. we also realize that failures are unavoidable. While we know that prevention is better than cure. The next chapter describes a few resources management techniques.much higher than the preventive actions require. criticality of the equipment and the priority. most situations in organizations warrant a mixture of maintenance types.4 Shut-down Maintenance Shut-down maintenance can either be a preventive activity or a corrective activity. this can be reduced considerably if the organisation has all the maintenance procedures and systems in place. are carried out after the equipment or plant is shut down. Shut-down maintenance can either be a preventive activity or a corrective activity. The cause is usually recorded for future analysis and corrective actions are prescribed.5. Depending on the availability of resources. Once an item of equipment fails. The maintenance manager is responsible for scheduling maintenance activities. 19. it should be closely associated or integrated with the resources management function. 20. The maintenance work that is carried out is not directed at the primary cause of failure of the equipment or shut-down. The work is deferred to a later date if the priority is low or the equipment is not so critical.
.5.5 Opportunistic Maintenance The maintenance work that is carried out is not directed at the primary cause of failure of the equipment or shut-down. If the priority is high or alternatively if the equipment is critical. Whatever be the choice of the maintenance policy. Five entities are important as far as the maintenance activities are concerned. The types of maintenance discussed in this section will help top management decide on questions like: should we carry out preventive actions? Or should we fix the equipment when it breaks? As mentioned earlier. Self Assessment Questions State whether the following statement True or False 16. Minor repairs which cannot be performed while the equipment is running. repair and replace certain other parts of the equipment. 18. 1. This approach to maintenance is called opportunistic maintenance. corrective maintenance work is scheduled and carried out. an emergency maintenance is carried out. the maintenance department personnel attempt to detect the cause of the failure. When a maintenance activity is carried out on an item of equipment there exists some opportunity to inspect. The cost of utilization of the resources is a indirect maintenance cost.

True
. Ignorance 3. and has been hastened by the fact that the loss of one hour of production is much more expensive today than it ever was before. From this state. 3. Explain Objectives and Functions of Maintenance. Resource Cost 5.1. chemical and fertilizer plants. True 8. This transformation has taken place in about 40 years and has brought about automation and increasing sophistication of plant and equipment. 5.6 Summary Until recently. maintenance of plant and machinery was a thankless job and the maintenance function was considered a necessary evil. Write a note on History of Maintenance. and integrated iron and steel works. Discuss Dynamics of a Maintenance Organisation. What are the features of Preventive Maintenance? 1.8 Answers Self Assessment Questions 1. False 7. nuclear power generating stations. What are the steps involved in Maintenance Organisation.7 Terminal Questions 1. it has now come to be accepted as an important function – one of strategic importance – particularly in the capital-intensive continuous-process industries such as power plants. Plant and equipment availability is of paramount importance and effective management of the maintenance function goes a long way in ensuring the attainment of the objective of maximization of availability 1. Production 4. Organisation-wide 6. 4. Maintenance 2. 2.

An important issue in manpower is that of determining the optimal number of skilled repair workers. However.1 Introduction For performing any maintenance activity resources are required. a maintenance job may require the services of a welder for just about an hour whereas the same job may require a fitter for more than four hours. The disadvantage of assigning a maintenance job to a repair gang or crew is that the manpower utilization within the gang is not effective. One solution to this problem would be to schedule individual workers rather than repair gangs. Techniques used for managing the maintenance resources are also discussed.8 Answers 2. In this study the characteristics of the maintenance resources are discussed. manpower. The procedures used are similar to those used for determining the optimal number of repair gangs required for carrying out maintenance activities. Queuing models and simulation have been used also for determining the optimal number of tools and facilities such that the maintenance costs are minimized. For example. can be used to determine the optimal number of welders. Queuing models. Queuing models. simulation techniques and queuing models have been used for determining the optimal number of repair gangs required to be deployed in a system. can be used to determine the optimal number of welders. which utilize the theory of minimizing the total cost of unavailability and labor. An important issue in manpower is that of determining the optimal number of skilled repair workers.2. requires some knowledge of the rate of failure (called arrival rate) and the repair distribution. not all skills are required for the same amount of time.2 Man Power Almost all the maintenance activities require skilled personnel and most of the activities require more than one skill such as welding. Objectives: After studying this unit you shall be able · To explain the characteristics of the maintenance resources · To define techniques used for managing the maintenance resources · To assess comparison of the available resources management techniques 2. The usage of the models. however. tools and facilities. which utilize the theory of minimizing the total cost of unavailability and labor. plumbers etc. A Maintenance job is usually performed by a repair gang or repair crew consisting of an optimal mix of skilled workers. Important among these are maintenance materials (spare parts). Basker. Manan
. rigging etc. Historically. fitting. plumbers etc.

not having the required spare part results in a stock-out cost. there is also a cost of ordering a re-supply of spare parts. Maintaining the spare parts in a store also incurs some cost. In general.and Husband have used the Monte Carlo simulation technique to determine the optimal number of repair workers required to perform the maintenance activities in a shop comprising a finite number of identical machines. and the number of repair gangs required such that the total costs (sum of labor cost and downtime cost) are minimized. 2. The objective of spare parts management is therefore to minimize the total of inventory holding. 2.3.1. Barnett and Blundell have used the Monte Carlo simulation technique to optimize the number of repair gangs and the size of the repair gangs given that the maintenance jobs generate demand for repair workers from three different trades’ mechanics. Newman and Brammer and Malmborg have utilized a material requirements planning/bill of materials approach to manage the manpower resources. 3.3.3 Spare Parts The spare parts (maintenance material) problems have been traditionally approached in three ways: 1. stock-out and ordering costs. Using the statistical inventory theory models. In addition to the holding and stock-out costs. electricians and pipe-fitters.1 Inventory Costs Every organization keeps spare parts so that defective and worn-out parts of equipment can be replaced.1 Statistical Inventory Theory Models 2. on the other hand. Using the material requirements planning/manufacturing resources planning (MRP/ MRP-II) technique. By holding spare parts in the inventory the funds of the organization are tied up which could have otherwise been invested in other activities. 2. Using selective control procedures along with some heuristics. two basic questions need to be answered: · How Much to Order? · When to Order?
. The objective is to determine the number of repair workers needed to constitute a repair gang.

The total inventory cost TIC = the holding cost + ordering cost. Mathematical models are however available to determine the timing of placing an order taking into consideration the characteristics of the demand during the lead-time as well as the lead-time itself. This provision normally takes the form of safety stock which is determined based on the service level.2. During this period. this is referred to as the lead-time. The following is an illustration of a basic inventory model which takes into account the holding and the ordering costs. If the annual demand for an item is D.00 The rate of interest is 20 per cent annually Then the optimum order quantity. Thus. where c is the cost per order.2 How Much to Order? Several models have been developed based on the principle of minimizing the total inventory costs.00 The unit price of the item is Rs. The complexity of the problem lies in the fact that neither the demand nor the lead-time is constant.3. 2. we have If The annual demand D for an item is 8000 units The cost of placing an order is Rs. the demand for spare parts resulting from the need to perform maintenance activities needs to be satisfied.1. Then the holding cost is given by where p is the unit price of the item and r is the annual stockholding rate related to the stock value. therefore. is 1000. The maintenance manager must make sufficient provisions to take care of demand during the lead-time because the cost of stock-out is undesirable in any situation. These models help determine what has been traditionally known as the optimum order quantity. Let Q be the ordering quantity. The service level is defined as the probability of not having a stock-out situation. Thus The minimum of TIC can be obtained by differentiating the above equation with respect to Q and equating the resulting derivative to 0. 100.1.
.3. 8. then the number of orders to be placed is given by The ordering cost is.3 When to Order? An order placed with a vendor for re-supply of spare parts takes some time to get filled. obtained by utilizing the above equation for Q.

the safety stock and the minimum and maximum inventory levels require to be determined for each of the items in the stores. medium. a few of which have been listed. paying equal attention to all the inventory items was not feasible. The following paragraphs describe some of the applications involving a combination of selective inventory control procedures.1 Most applications found in the literature make use of a combination of selective inventory control procedures because classification or categorization of items based on just one criterion is inadequate for managing the maintenance materials.3. Several procedures for classifying items into homogeneous groups are available. 4) _______________ and queuing models have been used for determining the optimal number of repair gangs.2 Selective Inventory Control Procedures The statistical inventory control techniques require that each item. irrespective of its criticality. be given equal importance. By this method the spare parts are classified into nine Basics Of Formulation Annual usage value of the parts Vital. Instead effort was concentrated on a few expensive and fast-moving items. difficult and easy to procure Procurement lead-times
. Technique Description ABC Pareto rule VED FSN HML SDE Table 2. The re-order quantity. 2) Several models have been developed based on the principle of minimizing the total _____________. During the days when computers were not available.Self Assessment Question 1) Maintenance job is usually performed by a _____________or repair crew consisting of an optimal mix. Items were categorized into homogeneous groups based on their characteristics. This is the principle of the selective inventory control procedures. low Unit price of the parts Scarce. 2. essential and desirable Criticality of the parts Fast. Ramani and Krishnan Kutty have utilized an ABC×VED classification technique where not only the annual value of usage of the part is taken into account but also the criticality of the part is given importance. slow and non-moving Usage rate of the parts High. 3) Every organization keeps spare parts so that defective and ___________ of equipment can be replaced.

If a substitute part is readily available then the part may be less critical. VED and the SDE classification procedures which results in eight categories of items as shown in table 2. while the categories formed on the basis of criticality of the parts are critical and non-critical. A reorder point-order quantity technique is used in conjunction with this method for replenishment of parts. makes use of a combination of ABC. These eight categories have been formed by taking only two categories in each of the three dimensions. The second dimension uses an SDE classification. Moreover. the stocking policy for a spare part in the V/S/F category is 2. MUSIC-3D. Although the selective control procedures make the managing of the multiple inventory items easier. A part may be classified as a critical part if the consequence of running out of stock is severe. which makes use of the ABC classification criteria. The two categories formed on the basis of sales value are high sales value and low sales value. and Ni is the standard deviation of the downtime cost (E denotes expectation). it should be noted that most of the classification criteria are subjective. For each of the nine categories. Saha and Mohanty have developed a spare parts stocking policy with an objective of minimizing the downtime of critical equipment. fi is the number of failures per unit time involving the part i.
. Duchessi.2. The first dimension. a range of service level is specified. A three dimensional classification technique has been used for the purpose. takes into account the annual usage value Bi of the part i and is given by where Ci is the price of the part and Di is the total annual demand. In other words. which is based on the procurement leadtime while the third dimension makes use of the FSN classification (usage rate). Tayi and Levy have utilized a two-dimensional classification method. The stocking policies for each of the 27 categories are determined using heuristics. a part may be called critical if the loss of production caused by non-availability of the part is very high. in the categories formed on the basis of lead-times are long lead-time and short lead-time. The first dimension utilizes a VED classification methodology.categories. statistical inventory control models or heuristics are utilized to determine the ordering parameters such as the order point and the order quantity.6m where m is the maximum quantity of parts requested at any time. It is the time required to replace or repair the part. For example. the multi-unit spare inventory control. The second dimension makes use of the criticality aspect of the spare part and is based on the revenue lost due to loss in production (Mi) which is given by where pi is the downtime cost per unit time per failure involving the concerned part. For instance. which categorizes the spare parts into groups based on their criticality. There are several ways by which the criticality of a part can be defined.

in turn. In addition to this. The components in the diagram have been described briefly.3 Manufacturing Resources Planning The manufacturing resources planning (MRP-II) technique has been used widely for managing production resources. in general. The demand for an inventory item is termed dependent when it is directly related to. All other constituents of the petrol engine are referred to as items. defines the constituents of an end-item. is made up of the piston. An end-item is an item at the highest level of hierarchy in the bill of materials. the petrol engine is an end-item.3. semi-finished or finished form. some applications involving management of maintenance inventories are also discussed. It is an operations as well as a financial system.2 2. a bill of materials file. As mentioned earlier in this section. a logic processor and a capacity planning subsystem. As seen in the figure. an inventory status file. in a raw. The bill of materials. Figure 2. any manufacturing organization would want to have the following questions answered: · How much to order? · When to order? Both these questions are also answered by the MRP technique.1 shows the components of MRP.2 shows the bill of materials for a petrol engine.3. It can also be considered to be an assembly definition. The components can either be manufactured in the shop or can be boughtout items. It consists of a master production schedule. the crankshaft assembly and the cylinder assembly. The central idea of MRP is to time production/acquisition of batches of parts/components so that they are available as they are required in assemblies. 2.1 The Bill of Materials The bill of materials defines how one or more items are brought together to make up another item. MRP-II possesses two basic characteristics which go beyond the closed-loop material requirements planning (MRP). the piston rings and the bearings. The bill of materials indicates that the engine consist of three subassemblies – the piston assembly. The piston assembly. Figure 2. This section provides a brief overview of the closed-loop technique. or derived from the demand of another inventory item.Table 2. The immediate
. It is also a system simulator. Later in this section.3. the application of MRP is also very simple. The technique is based on the principle of dependent demand.

The bill of materials also carries with it some other information such as whether the part is bought out or is manufactured within the organization.1
.
Figure 2. for example.predecessor of an item is called the parent item. The MRP technique uses the bill of materials for computing the requirements through a process called explosion or desegregation.2 two bearings (indicated in parenthesis) go into the making of a piston assembly. In addition to defining the relationship between items. is an item whose parent is the piston assembly. the bill of materials also indicates the quantity of an item that goes into making a parent item. The piston. As seen from Figure 2.

The master production schedule is constrained by the production plan. This would mean that 0. 2. Also.3. This is further broken down into a schedule for specific variants of carbide tools such as SPAN 50.2 Master production Schedule A master production schedule is a statement of production of end-items for a given planning horizon. the top management has budgeted 6 tones of carbide tools to be produced during the year. this can be broken down into 12 production months.2 Every item in the bill of materials is given a number or code such that no two parts have the same number.3. The master production schedule indicates the quantity of items to be produced in a given period.3. semi-finished and finished parts. It states what end-items need to be produced and how many needs to be produced in a month or week.
. There may be a case where an item is used in two different end items. Since the demand for carbide tools is all through the year.5 tones of tools need to be produced every month on average. which is a budget set by the management. level codes are assigned such that identical items used in different end-items are maintained at the same level. TPAN 75 and CPAN 75 that need to be produced. In order to make the computation of the requirements easy. The quantity of all the items to be produced in a given period must equal the quantity budgeted in the production plan as shown in Table 2. The total weight of the variants scheduled for production during the month when totaled equals the budgeted weight as shown in Table 2.Figure 2. As shown in Table 2.3. This includes raw materials. it may so happen that the items are used at two different levels.3. The priorities for the production of items specified in the master production schedule are set by the sales plan. The requirement at one level is computed first before proceeding to the next level.

2. 8.5 Rescheduling Process Scheduled receipts are orders which have already been released to the shop floor or to the vendors.5 Effect of Maintenance Types on Resources As mentioned earlier. A master production schedule is a statement of production of end-items for a given planning horizon. not be given equal importance. The statistical inventory control techniques require that each item. The bill of materials defines how one or more items are brought together to make up another item. In some cases. The manpower requirement is also known precisely. 9. The procedures used are similar to those used for determining the optimal number of repair gangs required for carrying out maintenance activities.3. Self Assessment Questions State whether following statement True or False. 5. materials on order may be received earlier than the due date while in some others the scheduled receipt may not be expected to be in the stock on time. it becomes necessary to trace the demand for an item to its source and this process is referred to as pegging. irrespective of its criticality. 2. 7. The scheduled receipts are taken into account while computing the net requirements.3. 2. in the case of a proactive perspective the maintenance activity is planned and the timing is also determined well in advance. This uncertainty may result in rescheduling of the receipts. Activities such as fixed-time maintenance enable managers to determine the exact number of parts required.4 Tools and Facilities Queuing models and simulation have been used also for determining the optimal number of tools and facilities such that the maintenance costs are minimized.Explosion is a process concerned with generating gross requirements. For audit purposes. This is a deterministic situation.
. 6. Scheduled receipts are orders which have already been released to the shop floor or to the vendors. The inventory status file will not contain up-to-date information about all the materials stocked in the stores.

Managers in some organizations carry out cannibalization as a last resort in order to meet the production requirements. Selective control procedures. have been used by industries for spare parts planning. if not both. If the equipment is critical. explaining the commonly used methods and discussing the work done by researchers working in the area of spare parts management. condition-based. cannibalization can lead to severe control problems at a later time. the maintenance activity is neither planned nor scheduled in advance. The basic purpose of this study is to provide the necessary background and present in a proper perspective the need of the development of an MRP based technique for the management of maintenance resources. Since failures occur randomly it becomes difficult to predict the resource requirements. As per the definition of maintenance. statistical inventory theory models and selective control approaches for multi-item inventories for spare parts planning and queuing theory and simulation for manpower planning. then the immediate requirement would be to restore at least one of the items of equipment to a working state. This perspective has been created by initially discussing the various types of maintenance resources and their characteristics. this happens to be an undesirable situation and should be avoided. Statistical inventory theory models and techniques for selective control have been discussed in detail. · Use standby equipment. This approach to maintenance is called cannibalization. such as the use of ABC and VED classifications. and the various models and techniques which are commonly used.6 Summary The problem of management of maintenance resources has been discussed. Cannibalization. If the required maintenance materials are not available in the stores then one option available is to replace the failed parts of one with the working parts of the other failed item of equipment. and corrective maintenance activities (and not just one of them). There are some
. namely. In some cases cannibalization is also practiced. · Build-up spare part inventories and tools. The technique should be able to take into account preventive. In order to reduce the impact of failures on the profitability of the organization the following techniques are usually adopted: · Increase the number of maintenance personnel. 2. and if manpower is a constraint. however. Consider a situation where two identical items of equipment have failed due to different failure modes. does not reduce the number of inoperable parts.In the case of a reactive perspective. If a failure occurs and the required resources are not available to restore the equipment to a working state the equipment is kept waiting in the repair queue.

ABC and FNS are more appropriate for standard spares such as pulleys. For spare parts. Repair gang 2. such as the re-order point and order quantity. and these models have their own shortcomings.7 Terminal Questions 1. or categorization. Such classification schemes. 3. Inventory costs 3. are utilized to determine the ordering parameters. 5. chains. researchers have suggested the use of multidimensional classifications.8 Answers Self Assessment Questions 1. Explain Man Power. in turn. Explain Master production Schedule. 2. give rise to a large number of classes of spares with each class having its own planning and control parameters. or heuristics. whereas VED and SDE may be more appropriate for special spare parts (ones which are used on particular equipment). 2. classification. Summarize Bill of Materials. statistical inventory control models. Briefly summarize effect of maintenance types on resources. Worn-out parts 4. 4. such as ABC×VED. For example. VED×SDE×FSN and ABC× VED×SDE. 2. sprockets and bearings. For the above reasons. belts.fundamental problems encountered in the use of selective control techniques for spare parts management and these are as follows: Such classification is always rather subjective and this is more so in the case of spare parts. based on just one criterion is adequate. In these cases as well. ABC×FSN. Simulation techniques
. Define Statistical Inventory Theory Models. Classifying spare parts into homogeneous groups using a classification scheme is difficult since different types of spare parts require different classification schemes.

· Report on the performance of the overall maintenance system using standard indicators. 3.
.2. Predict failures to a chosen level of confidence. Inventory management subsystem. Vendor management subsystem. 3. 5. Schedule preventive maintenance work. 5. the scope of the system should be clear. Store maintenance data including failure and repair data. Plan maintenance work – ensure materials.Objectives: A maintenance management information system must help you to · Schedule the Maintenance activities. 4. 2. · Optimally utilize maintenance resources. 2. · Plan procurement of resources.2 Functional Requirements Before designing the information system. should have the following functions. 4. Requirements can be gathered by interviewing the prospective users or circulating questionnaires. at the least. Update data when a failure or preventive maintenance activity is initiated and completed. Subcontractor management subsystem. manpower and tools would be available. Equipment maintenance function. 3. Track overall maintenance function performance. hiring of subcontractors and arranging facilities. 6.1 Equipment Maintenance Function The equipment maintenance function needs to perform the following: 1. The functional requirements of the information system should be gathered first. 1. A maintenance management information system. 3. Work order management subsystem.

Track status of manpower. Plan capacity. Track utilization of manpower. 2. Track maintenance costs. tools and facilities.4 Vendor management function The vendor management function needs to perform the following:
. Convert critical maintenance requests into work orders. Produce reports as desired by the maintenance manager and top management. List pending work. 6. 9.2 Work order management subsystem The work order management function is required to perform the following: 1. Alert the maintenance manager to place orders for materials as planned and in the required quantity. 3. 3. Print reports as desired by the maintenance manager and top management. Schedule work visually. 3.3 Inventory management function The inventory management function has to do the following: 1.2. tools and facilities. 7. 6. 2. 4. 8. Schedule release of planned orders (materials). Track status of work in progress. Generate work orders for preventive and corrective actions. 7. 5.2. 3. 5. Store and maintain inventory data including skills and tools. Create maintenance requests. 4. Produce reports as desired by the maintenance manager and top management. covering manpower. materials and tools. Update materials inventory data as and when an issue or receipt of materials occurs.7.2. 3.

3) The equipment maintenance function needs Schedule preventive maintenance work.6 General Information Systems Specifications The general information systems specifications need to perform the following: 1. Produce reports as desired by maintenance manager. Track progress of subcontracted work.1. 2. 6. Track cost. In order for a system to be efficient. 3. 3.2. 2. Validate data entry. Devise metrics for evaluation of vendors.5 Subcontractor management function The subcontractor management function must: 1. Maintain vendor information. 2) The work order management function is required to perform Plan capacity. Make on-line data entry. 3. Print related reports. 3. Organize skills provided by subcontractors. 5. 1) The subcontractor management function must not maintain data related to subcontracts. Maintain data related to subcontracts. top management and middle management. each level of management needs to have access to the required information and should be able to extract the data which is needed. 2. Track quality of subcontracted work. Self Assessment Questions State whether the statement is true or false.2. 3. Cater for three levels of users’ administration. 4.
.

Each year DOE and the contractor review the contract and the progress of work as part of the annual budget process. · Execute the work. safety and protecting the environment. requirements stated in the contract and the annual budget process form the top-level means of identifying the work that will be performed. scheduling and performance of the work that has been accomplished. other programs may be developed by the contractor in furtherance of contract execution. The statement of work. · Select the specific work that will be planned.
Mechanics
The contract between DOE and the contractor provides the top-level mechanisms for work to be identified. The statement of work in the contract provides a description of the mission-related work that DOE expects to be performed. Whether mandatory or voluntary on the
. and · Critique the planning. · Schedule the work for performance. Identify Work Concept This element describes the processes and tools put in place that determines the work that a contractor performs. Contractors develop management programs to execute much of the work of contracts. On a day-to-day basis. A number of these programs are mandatory.4) General information systems specifications will not validate data entry. · Close the work item after completion. At the top-level these processes and tools include the contract with DOE and management programs committed to by the contractor to execute the statement of work and requirements in the contract. 5) The vendor management function needs maintain vendor information. they would entail routines used to monitor attributes important to mission execution.3 Work Management Process These steps to be followed in work management process are: · Identify the work that needs to be performed. · Plan that work. 3.

From this process the work to be planned and executed in a given year is identified. at a high level. Workers are encouraged to be vigilant in monitoring facility conditions for system or equipment problems. Work requests not supporting the current mission. They provide the opportunity to proactively manage the identification of emergent work. These routines can include Technical Surveillance Requirements/ Limited Condition of Operations TSR/LCO surveillances. The Select Work element funnels the work requests through a validation or screening process to determine those work items needing to be completed. these management programs provide one of the primary paths for work to be identified. Program and project plans are updated with the information developed during the annual budget process. While the threshold for identifying work items needs to be sufficiently low to all capture work items. In furtherance of management programs. Work management systems are put in place by contractors to collect work requests into a single place. system and environmental parameters. Work is also identified on a daily basis. Select Work Concept Management programs identify the operational activities and routines that need to be completed to meet mission deliverables. a continuous process. or improvements. Other types of work are converted into work requests.part of the contractor. On-going assessments or reviews may identify the need for corrective actions. which are initiated by personnel who identify work that needs to be performed to allow the work item to be entered into a work management system. and similar repetitive procedures. contractors often put routines in place.
Management
The annual budget process provides contractor and DOE management the resources to manage the work that is identified for further planning and execution. These include work requests. The identification of work is. The discovery of new information may result in the need for additional research and development or design changes to existing systems and equipment. an identified project or specific facility need are screened out and no further resources applied to their resolution. environmental monitoring. prioritize and coordinate the management of several categories of work. operator rounds. no contractor has the resources to complete every identified work request. The schedule is also a tool that ensures that work is properly identified. After the work
. changes. therefore. Routines are executed to monitor equipment. This process compares the work accomplished and that which remains to the funding that DOE believes will be available to execute work in the coming years. they provide a method to track. Additional management tools that are used in the work identification process also support other elements of the work management process.

Effective work management processes utilize a graded approach to resolving work requests. These tools should be reviewed to determine whether duplicate items are already entered into the system. or required plant operational modes to facilitate tracking and planning and then entered into the work management system. or management commitments. Knowledge of these drivers allows effective prioritization of work planning efforts. traded off with lower priority work or put forth as a candidate for additional funding. equipment identification.request has been validated a formal work order is entered into the work management tools used by the contractor. · Need Date: Work requests must clearly indicate any deadline dates and the estimated time period for completing the work. operational requirements.
. · Work Cost: Work requests may be identified that will require funding that is beyond that available to the contractor. Work may be tied to contract milestones. and interface with mission requirements. or. Work requests that have equipment impacts must be evaluated and the systems configured to protect equipment and workers. etc. The work may be simple enough that no initiating work documents are required (so-called “tool pouch” or “quick fix” items). The work selection process starts with a work validation.
Mechanics
Work selection is a continuous process to handle the work requests identified on a daily basis. A strong validation process incorporates two-way communications with the work request identifiers. If the work item is a duplicate it should be screened out. Location of the work. coded with respect to like components and systems. This validation process evaluates attributes of the work items to determine if the work item should be processed through the work management system. Work requests that are clearly not going to be accomplished due to cost impacts should be screened out at this point. may all provide key information needed to properly validate the work. stay in compliance with the established safety basis and operating requirements for that facility or project. Or the work request may require a documented resolution. if sufficiently important. · Operational Impact: Work requests that have immediate impact on the health and safety of contractor personnel need to be processed rapidly. · Work Duplications: Contractors use Work Management Tools to track work orders. This second type of work will normally be given a relative priority. Attributes evaluated include: · Work Scope Identification: A clear scope statement is necessary to understand what work activities are necessary. problem symptoms.

Those work requests entered into the work management system result in the generation of work orders. Mature work selection processes incorporate an understanding of a graded approach to work planning.

Management
Contractors need to clearly define who has responsibility and authority to perform the validation activity for their facilities and projects. The validation authority typically resides in the Operations organization because they are responsible for mission execution and normally retain configuration control of the facility systems, structures and components. The work management process descriptions need to define the planning processes used by the contractor staff. Requirements for the type of planning required, based on potential mission impact, hazards analysis and complexity of the work activity, are critical to decision-making during work selection. Plan Work Concept This element describes the process of taking a defined scope of work that has been selected for planning and developing/packaging technical documents to safely and efficiently perform that work. This process includes identification/incorporation of applicable technical specifications and requirements into technical documents, identifying and mitigating job hazards, identifying and obtaining required permits, developing work instructions, and defining post activity acceptance. Mechanics An initial step in planning work is determining what type of work execution vehicle will be used to perform the work. As previously discussed under Work Selection, this decision has often already been made, on a preliminary basis, prior to the initiation of Work Planning; however, it is confirmed as part of this element. Is the work to be performed with a very simple work package where the worker has the knowledge to perform the work and little or no instruction is required or will the work require a work package with more detailed instructions? The following criteria might be used to determine whether work can be performed using a very simple work package: · No medium or high risk activities. · No activities requiring hold points. · Will not alter configuration of equipment from documented design. · Will not present any unusual hazards.

· No hands-on work with radioactive material except incidental or routine work activities that involve low potential of worker exposure or workplace contamination. · No opening of contaminated systems, components, containers. · Minimal external coordination required. · “Skill-of-the-Craft” Work. Such tasks should be documented in a work package by the Field Work Supervisor (FWS) and released to work by operations and documented on the document releasing work.

Management
Work management systems are often put in place to collect work requests and maintain and file documents in a single place. They provide a method to track, prioritize, and coordinate the management of several categories of work. They also provide a means for the work planning organization to interface with the operations organization and ensure that work is moving through the planning pipeline in a manner that supports mission execution. Schedule Work Concept Schedules are tools used by work management organizations to communicate and coordinate work activities. This element describes the processes and tools associated with establishing schedules. Typically, work is identified from various sources (missionrelated commitments, Authorization Basis requirements, maintenance routines, etc.) and flows through a “rolling work week process” (described below) into an integrated schedule. The rolling work week concept is typically established based on either an 8 or 12 week duration.

Mechanics
Most sites have developed a fairly common set of schedules to implement graded approaches to conduct of operations. These commonly include a Plan of the Day (POD) along with a slightly longer view, often one week (so-called Plan of the Week, POW). Various methods exist to move information from longer-term schedules to these two short-term scheduling tools. The rolling work week concept provides an effective tool for managing the development of schedules. It involves setting a specific time frame (or “window”) within a longer-term schedule on which to focus increased management attention. Common time frames are eight to twelve weeks.

· For work that falls within the work window, increased emphasis is placed on planning, detailed schedule concerns and coordination of the work. This time period of increased attention allows: o Optimization of planned outage windows, scheduling all tasks that require particular facility conditions or that impact production commitments; o Development of a detailed technical sequence for complex jobs; o Addressing only items that need to be scheduled in detail, i.e., they require coordination of resources, complex work, etc; o Grouping of similar work to efficiently use resources and equipment by facility mode, available space, system/equipment; and time to verify that parts are available and staged. The work planned during the work window is “Locked-In”, that is, committed to by all concerned, two weeks in advance. This lock-in process adds discipline to the scheduling process and provides focus for final work preparation and coordination. After lock-in, the schedule is under a formal change control process; this encourages people to only lock in work that is truly ready to work. This level of planning and commitment permits the development of precise resource loaded schedules; it supports aligning support resources to the schedule and permits other detailed preparations such as verifying that fully-trained workers are available. This level of planning and scheduling attention also improves task readiness, it allows crews time to review work in advance of working. A formal post work week critique is held to evaluate what got done, what didn’t get done and why. It should be clear from the level of effort inferred above, that the implementation of a rolling work week process requires a commitment from all organizations to make the system work. Work on the rolling work week is facilitated by the existence of schedules that integrate all important work. Management Management tools for a successful scheduling process include: · Senior Management involvement (Frequent and Regular) – Critical Path Meetings · Accountability meeting – weekly schedule commitment meeting · High level schedule change control authority once work is locked in · POD – A daily meeting intended to review facility and schedule status

· Assemble tools and material at job location. Applicable work instruction prerequisites are completed to ensure readiness to work. Example components of work execution include the following: Preparations: · Contact job support personnel as required.· POW – A weekly meeting intended to review and status the higher level facility schedule · Rolling work week process – described above · Outages – scheduled periods where equipment systems or facilities are available to perform pre-determined work · Metrics – tools used to measure success of schedule performance · Documentation of key scheduling assumptions – essential to the development of baseline schedules Execute Work Concept This element describes the processes and tools associated with the actual performance of the work. · Complete rigging preparations. ensures that procedures and references are the latest revision and that all of the required permits are issued and up to date. This element is centered on the first-level supervisor (the person directly overseeing the work crew) and the crew that is engaged in the performance of the activity. This work should be completed in parallel with establishing worker protection and industrial safety requirements. · Build scaffolding and install lead shielding. Mechanics For each assigned task.
. · Remove insulation. · Assemble required test equipment. The execution of work begins when the work package is released for work by Operations and runs through the completion of work in the field or facility. the first-level supervisor performs a final review of the work instruction.

and water requirements. tents. Formal programs to have management observe work in the field will provide not only
. · Finish prefabrication work. · Build contamination control devices (catch basins. · Set up welding equipment if required. job hazards analysis. power. field walk-downs. Pre-Job Brief: · Scope of the task · Review of prerequisite section of the work instructions · Responsibilities of all participants. water storage/recovery systems). The supervisor documents relevant as-found conditions and the work performed. Management Management tools put in place to monitor work execution include the Plan of the Day or other work progress meeting. environmental or radiological hazards of the task from the work document. the first line supervisor reviews the instructions for a complete and accurate work history and performs post activity testing and any rework identified by the post activity testing. or facility knowledge · Potential abnormal events and contingency plans After completing preparations and getting their work crew prepared to perform the job. Radiological Work Permit. and identifies all discrepancies and incomplete work items. which monitors the day-to-day progress of work execution. the first line supervisor completes all system/equipment checks described in the work instructions to return equipment to service.· Provide necessary temporary air. including expected worker radiological recovery actions · Job-specific hazards and their controls · Applicable precautions and limitations · Required safety equipment · Discuss hold points with employee(s) responsible for the completion of the hold point and employee(s) performing work immediately before or after the hold point · Industrial. the first-line supervisor oversees and directs the work activities in accordance with the approved work instructions. As the work completes. Finally.

including quality. normally in the operations organization.status. are satisfied and test results are approved. capturing repair history. Verification: · Verify all administrative and technical requirements. as appropriate. These steps include the process of verifying that work has been completed. Important attributes of these processes are discussed below. e. but a more accurate feel for work difficulty and potential coordination issues. · Ensure condition tags and other documents are in the completed closure package prior to returning it to the Work Management Center. resolve any deviations. · Update the files for the affected system/equipment. Schedule updates. Documentation associated with the work evolution can then be signed off. calibration and preventive maintenance data into the Work Management System.. a number of sites use standard computerized templates to capture relevant historical information.
. regulatory and safety basis requirements. Close Work Concept Work can be closed and declared complete when defined requirements in the approved work package have been met.g. an inventory of equipment and parts used and feedback to the work management process. · Update as-built drawings. . or exceptions have been authorized by the person responsible for accepting the work. returning (or turning over) equipment and systems to operations. The system/components can be returned to operations subject to any controls defined in the work instructions. Documentation: · Document work completion against requirements. documenting the completion of work. · Dispose of excess materials and waste properly. · Remove all temporary/test equipment and restore system/components to operable status. or authorized incomplete/open work items. based on work completed also provide feedback on work execution. Mechanics The work closure process can be described as several related steps.

Return to Operations: · Review work activity and all testing for system/equipment operability. Critique Work Concept This element describes the processes and tools associated with performing a critical analysis of work to ensure that issues.· Retain the closure package in accordance with the Site’s records retention requirements. · Evaluate the authorized incomplete/open work items for any operational impact concerns. Inventory: · Document material used. e. the first line supervisor should consult with the work planner and the systems engineer as needed. and return the system/equipment to the required configuration to support facility operations. issues. and lessons learned. the previous work week (Work Week Critique) period. and ensuring completion of the work closure functions.g. · Return unused parts to the warehouse. · Verify required procedure. ranging from individual job post work critiques to critiquing all of the work performed by a group or a facility within a specified time period. drawing and training updates are completed prior to placing the component(s) in service. Improvement opportunities are
.. Management The first-line supervisor is responsible to verify work completion against requirements defined in the approved work package. · Accept the system/equipment for operability and return to service in a timely manner. and incorporated into subsequent work. Work critiques take on many forms. If there are authorized open items. the work package should have been changed and procedures amended by the appropriate formal documentation. improvements or lessons learned are identified. · Release all remaining clearance tags.) process takes selected jobs and critiques them to identify good practices. Mechanics The post work critique (ALARA. etc.

typically covering the previous weeks work activities · Work Week Critique Attendance: Work week critique targeted audience should typically be that of Facility Senior Management. but was not & what the issues were which prevented that work from being accomplished. including: § Schedule & Cost Performance § Manpower Utilization § Emergent Work § Backlog · Action Item Tracking: A formal process in which action items from the Work Critique meeting are assigned responsibility & tracked through completion. The applicable post work critique output should be discussed in the work week critique process described below. including the specifics regarding what was accomplished. The work week critique process is a continuous improvement process. what was initially intended to be accomplished. Issues should be trended to identify programmatic issues.typically formally documented and followed to closure through a commitment tracking system. etc.
Management
Management tools for a successful critique process include: · Weekly critique meeting · Regularly scheduled meeting following each work week to critically review performance of the previous work week (attended by Senior Management)
. whereby all groups involved in work execution meet to perform a critical analysis of all aspects of the week performance. · Work Week Critique Report: A formally prepared report which comprehensively addresses the work week being analyzed. o Metrics which track and trend the work week elements. including Emergency. Emergent. · Work Week Critique Meeting: A regularly scheduled meeting used to perform a thorough analysis of the work execution. The report should also include: o A breakdown of the types of work scheduled & accomplished for the week.

2. Explain Schedule Work in Detail. Explain Functional Requirements in Work Management. normally in the operations organization. Management programs identify the operational activities and routines that need to be completed to meet mission deliverables. Work can be closed and declared complete when defined requirements in the approved work package have been met. Identify Work describes the processes and tools put in place that determines the work that a contractor performs. Execute work describes the _______ and ______ associated with the actual performance of the work.· Appropriate Metrics including tracking and trending · Standard Critique reports · Action Item Tracking / Accountability · Worker feedback Self Assessment Questions 6) Management tools for a successful critique process include _________. Explain briefly Identify Work in Work management Process. Explain components of work execution.4 Summary The Work Management process requires the full support of the entire organization. 3. 4. or exceptions have been authorized by the person responsible for accepting the work. 3. Describe Close Work in Work Management Process. 9) Identify describes the processes and tools put in place that determines the work that a ________ performs. Management programs identify the operational activities and routines that need to be completed to meet mission deliverables. 5. 7) _________ can be closed and declared complete when defined requirements in the approved work package have been met.5 Terminal Questions 1.
. 3. 10) ___________________ systems are often put in place to collect work requests.

2 The Maintenance Function 4.5 Summary 4. The reasons for breakdowns were many: development of high temperature in the bearings. overheating of motors. the machines caused a great deal of anxiety to the management by failing quite frequently and unexpectedly. breakage and slips of gear and belt drives. In the initial stages. etc.4 Maintenance Economics Breakdown-time Distribution Preventive versus Breakdown Maintenance (Single Machine) 4. The breakdown of the machines resulted in a great loss of productive time and also led to several problems such as not being able to meet due dates. misalignment of shafts and pulleys. and were immediately commissioned. failure of insulation in electrical circuits.OM0006-Unit-04-Emergencies or Breakdown Process Paper: ISO 90012000/Qs Elements
Unit-04-Emergencies or Breakdown Process Paper: ISO 9001-2000/Qs Elements Structure: 4.1 Introduction Objectives 4.7 Answers 4.6 Terminal Questions 4. and low morale of workers. especially while processing important jobs.
. one-year back.1 Introduction The turret lathes and gang drills were acquired second-hand. formation of sludge’s and corrosive compounds on the machine parts.3 Maintenance Strategies Corrective or Breakdown Maintenance 4.

In order to combat these problems. Preventive maintenance of a machine consists of dismantling the machine and checking all its important parts and making the necessary adjustments and replacements. Maintenance work on a machine requires both workers of a crew. Objectives After studying this unit you shall be able to · Explain the functions involved in maintenance · Recognize the strategies of maintenance · Distinguish between preventive and breakdown maintenance · Evaluate the economic aspects of maintenance 4.
. availability. is any activity carried out on an asset in order to ensure that the asset continues to perform its intended functions. The machine operators can only operate the machine when they are in working condition. Such maintenance is expected to reduce the frequency of machine breakdowns. the proprietor of the workshop advertised for maintenance specialists for the turret lathes and gang drills. he selected four technicians for employment. The four workers were divided into two crews. After a long search. It improves the systems overall reliability. or to restore to its favorable operating condition. and consequently higher production efficiency. The maintenance crews can do breakdown maintenance as well as preventive maintenance for all the four machines. or to repair any equipment that has failed. and cannot attend to any repairs or maintenance.2 The Maintenance Function Maintenance. The technicians accepted the job under the condition that if ever they are required to work in the second shift on a day. or to keep the equipment running. they are to be paid overtime. Maintenance is defined as ‘any action that restores failed units to an operational condition or retains non-failed units in an operational state’ or ‘an activity carried out for any equipment or asset to ensure its reliability to perform its functions’. the proprietor had considerable difficulty in finding he maintenance specialists. Minimizing these adverse effects is the role assigned t maintenance. reduced downtime and cost of operation. Minimizing the failure count or their adverse effects leads to increased safety. Machine and component failures can trigger incidents or cause costly production interruptions. As he wanted technicians with experience on the specific machines he had. each crew consisting of two workers. to most people.

The maintenance function plays a supporting role to effective operations. and · The cost of operation and maintenance is minimized. as well as the quantitative and cost standard of outputs. product quality and customer service profile of the organization. From a simple expectation of keeping equipment running or restoring it to the desired operating condition. · Safety is ensured. environmental integrity. First Generation Second Generation Third Generation · Fix it when broke · Scheduled Overhauls · Condition monitoring · Systems for planning · Design for reliability and and controlling work maintainability · Low-tech computerization · Hazard studies · High-tech computers · Failure modes and effects analysis · Expert systems · Multitasking and teamwork Table 4. The evolution in the maintenance thought process is rooted in the changing complexity of industry itself. energy efficiency. It determines the risk-safety. Over the past years. the significance of maintenance and its role in plant operation has changed significantly. · Down-time is minimized. management today sees a much larger role for maintenance. in addition to its traditional roles of enhancing plant availability and lowering costs.1 shows the evolution of the maintenance philosophy.1: Evolution of Maintenance Philosophy Table 4. Maintenance efficiency is viewed as an integral part of business effectiveness. The evolution can be seen to cover 3 different generations of thought.
.The objectives of maintenance are to maintain equipment and facilities in such condition that: · They give trouble-free service and output at rated capacity. It ensures that the equipment is able to maintain quality standards.

Factory equipment was basic and repair and the restoration process was simple. Downtime did not matter much and no need was felt to treat maintenance as a high priority issue. The failures that do occur during the period are truly random. These have led to major developments in maintenance philosophy based on manufacturing reliability systems. this pattern manifests itself when a collection of machinery is subjected to rigorous operation. 4. expert systems and continuous improvement programs have developed. there is a rather high incidence of early failures. the weak components from the infant mortality period have either been repaired or replaced. Second Generation (1950-70) – The second generation emerged as the result of growing complexity in equipment and plant design. During the infant mortality period. Repairing and restoration had become more difficult and special skills and more time was needed to maintain and repair equipment. In practice. there is a definite pattern of lifespan. As this dependence grew. First Generation (1930-40) – The first generation represents the earlier days of industrialization where mechanization was low. Most equipment that survives infancy will continue to perform with few failures occurring. As these components drop out one by one. or sheer quality deficiency in their manufacture. During this period.1. This is the useful period of the machine. but they are thought to be at least partially due to abrupt changes in stress distribution in the components. 2. fatigue due to flaws in the molecular structure of the metals or plastics involved. called infant mortalities.3 Maintenance Strategies
. Researchers into the reliability of equipment recognize that within a collection of machines. primarily due to the presence of weak or substandard components or design inadequacies in not properly understanding the operating conditions. unpredictable and cannot be prevented by additional testing or burn-in of the components. Hence. the failure rate keeps decreasing until a relatively low constant level is obtained. The reason for the occurrence of these failures is not fully understood. Among collections of equipment. 3. the failure rate is high. the growth of mechanization and automation has become more complex and even small breakdowns in equipment affect the operation of the whole plant. industry became increasingly dependent on these complex machines. With increase in mechanization. there was an added interest created in the field of maintenance planning and control systems. downtime became a problem and management tried to find means and ways to minimize and prevent these failures. How Equipments Fail Maintenance is concerned with controlling the condition of equipment. reliability and availability have become key issues. As maintenance costs started to rise sharply relative to other operating costs. Third Generation (after the 1980’s) – Since the 80’s. This led to the concept of preventive maintenance.

equipment. maintenance functions may be identified as primary or secondary functions. b) Plant protection.. Some of the common approaches to maintenance are as follows: · Breakdown maintenance · Preventive maintenance · Predictive maintenance · Proactive maintenance Type of Maintenance Strategy Maintenance ApproachSignificance Fix-it when broke Large maintenance budget Scheduled Maintenance Periodic component replacement Condition-based Maintenance decision Monitoring based on equipment condition Detection of Sources of Monitoring and Failures correcting failing root causes Maintenance Strategy Breakdown Maintenance Preventive Maintenance Predictive Maintenance
Proactive Maintenance
Although the scope of maintenance will vary depending on the type of industry.Over the years. d) New installations of equipment and buildings. etc. b) Generation and distribution of utilities. its size. c) Alteration to existing equipment and buildings. The primary functions are: a) Maintenance of existing plant. many new approaches have been advocated as maintenance strategies that are intended to overcome problems related to equipment breakdown. buildings and grounds.
. the prevalent management policies. The secondary functions are: a) Maintenance stores.

the maintenance technician must verify that the system is again successfully operating. action must be taken to address the cause. breakdown maintenance.
. usually by replacing or repairing the components that caused the system to fail. · Corrective maintenance may be defined as the repairs carried out to restore equipment. 4. Corrective maintenance is typically carried out in three steps: a) Diagnosis of the problem: The maintenance technician must take time to locate the failed parts or otherwise satisfactorily assess the cause of the system failure. so as to restore it a specified operating state. · Corrective maintenance strategy has no routine maintenance task and therefore is also described no scheduled maintenance strategy. a properly designed fault reporting system must be instituted and similarly. The goals and objectives of corrective maintenance management are. b) Repair and/or replacement of faulty component(s): Once the cause of system failure has been determined. · Restoring a failed system usually involves replacing or repairing the component that is responsible for the failure of the overall system. c) Verification of the repair action: once the components in question have been repaired or replaced. Corrective maintenance is performed at unpredictable intervals because a components failure time is not known a priori. It is also called. the rectification of the fault should be processed in the same manner as for planned maintenance work schedules. · The approach to maintenance is totally reactive. and b) To do this in a cost effective manner.c) Waste disposal. which has broken down or developed a fault. · However. the repair work is performed only after a piece of equipment has failed. To rectify the problem. d) Salvage. corrective maintenance is periodically performed on the equipment. maintenance is activated on breakdown.1 Corrective or Breakdown Maintenance This is one of the earliest maintenance strategies implemented in the industry.3. It consists of the action(s) taken to restore a failed system to operational status. and as the name suggests. a) To restore the faulty equipment to a healthy operating state as promptly as possible.

The growth of __________ and automation has become more complex. thereby eliminating or at least minimizing the failures. and the adoption of other maintenance practices may reduce interruptions to production. the practice of attending to machines only after they have broken down may be uneconomical. Even where capacity is not a constraint. proper feedback to the design department may lead to alterations in design that will reduce or eliminate failures.· Corrective maintenance in a broader perspective may also include activities related to correcting potential causes for failure or malfunction that might not have been adequately considered when the equipment was designed. the failure of any one of its parts can cause a breakdown of the machine. each part will have a different failure distribution. Self Assessment Questions 1. 2. In such cases. 4. Machine and component failures can trigger _________. management must know how the breakdowntime is distributed. what are its cost implications? 4. and where production interruptions may be negligible. In such a situation. 3. 4.4. Moreover. Restoring a failed system usually involves _________ or repairing the component. The first generation represents the earlier days of ___________ where mechanization was low. · Where capacity and demand are close. 5. breakdowns may affect production and thus reduce profits.1 Breakdown-time Distribution In order to establish the cost implications. the breakdown maintenance practice may be costlier than other maintenance strategies. For example. maintenance engineers should be allowed to consider the possibility. _________ Maintenance strategy has no routine maintenance task.4 Maintenance Economics Maintenance policy refers to an organization’s policy in respect of the maintenance function of a set of equipments. if careful observations of repeated failures of an equipment or system suggest that the remedy lies in correcting the system. Such a distribution will show the frequency of maintenance-free running times for a given number of operating hours. But in the case of a complex machine. A simple machine with few moving parts will probably have breakdowns after a fairly large number of maintenance-free runtime hours. The breakdown time distribution of the complex machine probably will
. The decision of maintenance policy is more of an economic decision rather than a technical one. As maintenance is an economic decision.

show greater variability than the simple machine even though it may have the same average. while curve ‘b’ represents a more complex machine. C & D. and the ‘run-times free of breakdowns’ as the ‘x’-axis. B = 0. The same data that we have used to plot figure 4.9 ‘0. Equipment can be considered as a total system with its sub-assemblies as sub-systems. Say to obtain the ‘a’ curve in figure.8 ‘0. maintenance free run-time as that of the simple machine. and the reliability factors are A = 0. and plot this against the run-time. the reliability of the total system would equal the product f reliability factors of each of the sub-systems. It also shows that it is only after a few periods of trouble free running.e. Curve ‘a’ exhibits low variability from the average maintenance free breakdown-time ‘Ta’. i. subtract from 100 the figure 4. The total system reliability will be the product of the reliability of each individual system.7 = 0. say A.7..4 can be used to plot the percentage of breakdowns that exceed a given runtime as the ‘y’-axis. If we assume that the failure of any one of the sub-systems can cause the failure of the entire system. that one can be sure the machine will operate reliably.8 ‘0. The variability depicted by curve ‘c’ is typical of complicated equipment that needs ‘fine’.free run-time as the other two but the distribution has much wider variability. which exceed a given free-run-time. In this case. Curve ‘a’ depicts the behavior of a simple machine. it would amount to (0.
.
T3 = Average free run time free of breakdowns Figure 4.8. if the total system has four sub-systems. B. curve ‘b’ is the exponential distribution and exhibits medium variability and curve ‘c’ exhibits high variability. adjustments before it can give reasonable trouble-free service.2 represents a graphical description of the degree of variability in free-run-time.9.8 and D = 0.40). For example. The frequency distribution curve ‘c’ has the same average maintenance.4 for the percentage of breakdowns.2 Figure 4. By reliability we mean the probability that the system will give trouble free service. C = 0.

2 Preventive versus Breakdown Maintenance (Single Machine) Consider a preventive maintenance schedule. the average maintenance free run-time. Figure 4. shortening the preventive maintenance cycle can reduce the number of actual breakdowns.4. and the length of the standard preventive maintenance cycle. In actual practice. the situation is slightly different. is equivalent to ‘Tr’ (maintenance free run-time) plus ‘Tm’ (the time take to do the preventive maintenance). the running time between the preventive maintenance and the breakdown plus the time taken to repair the breakdown. In such cases. more breakdowns are likely to occur during the course of the standard period. preventive maintenance should be performed just a little before normal breakdown is likely to occur. This can be considered the standard preventive maintenance cycle time. Ideally. This preventive maintenance work takes a time ‘Tm’. Since preventive maintenance is meant to reduce the total plant down-time particularly unscheduled event – its timing and frequency are important. there will be breakdowns that occur before the equipment is shutdown for preventive maintenance.Figure 4. The total time period ‘Ta’. inspected and parts replaced. the machine is shutdown. after which the equipment is ready to work. ’Ts’ can be considered the breakdown cycle.4: Breakdown-time distributions 4. which after a machine has been running for fixed time ‘Tr’.5 gives the percent of time a machine is working for the three distributions of breakdown-time shown in Figure and the ratio of the standard maintenance period to
. When this happens. over a period of time. If the distribution has greater variability. The probability of occurrence of a breakdown in the two different cycles depends on the specific breakdown-time distribution of the equipment.

as there is better predictability of when breakdowns are likely to occur.
Figure 4. The percentage of machine running time depends on the ratio of the standard maintenance period and the average run-time. the machine works for a small percentage of time. it is assumed that either preventive maintenance or repair puts the equipment in line for a running time of equal length.5: Present of time when the machine is working and breakdown distribution Certain generalizations can be made from the above three graphs. since a low ratio would mean too many machine stoppages. like those depicted by curve ‘a’. there is an optimum value for the standard maintenance period. Unless the preventive maintenance time is less than the repair time. Second. it can also be seen that for curves ‘b’ and ‘c’ an increase of the ratio results in an increase in the percentage of machine running time. ‘Ts’. there is little gain in
. preventive maintenance is highly benefited to machines whose breakdown time distributions have low variability. It can be seen that for low values of the ratio of standard maintenance period to average maintenance free runtime. From figure. but only till a peak is reached after which lengthening standard maintenance period seems to reduce the percentage of machine running time. a standard preventive maintenance period can be set in such a way that the total downtime is reduced. Such a relationship is shown for the three different breakdowns time distributions. and hence less availability. there is a similar increase in machine running-time. ‘Ta’ for a given breakdown-time distribution.average maintenance-free run-time. This suggests that for breakdown time distribution with low variability. First. In the case of curve ‘a’ (for breakdown-time distribution with low variability). In this type of situation. the relation of preventive maintenance time to repair time is important. This is obvious.

10. If preventive maintenance is equal to. both in terms of contribution earned by them as well as their criticality because of their propensity to break-down. The percentage of machine running time depends on the ratio of the standard maintenance period.6 Terminal Questions 1. 4. The probability of occurrence of a breakdown in the two different cycles depends on the specific breakdown-time distribution of the equipment.preventive maintenance. Additional stoppage time because maintenance crew cannot start repairing immediately after the breakdown has occurred. it is better to perform corrective or breakdown maintenance. The breakdown time distribution of the complex machine probably will not show greater variability than the simple machine. 8. What are the Maintenance Strategies?
. or more than the time for repair. 2. Maintenance policy will not refer to any organization’s policy. Self Assessment Questions State whether the statement is true or false. an increase in the standard period would mean less number of preventive maintenance cycles and more repairs. 9. 4. Equipment cannot be considered as a total system with its sub-assemblies as subsystems. In general. when the repair time is equal to maintenance time. Effect on production losses if plant shutdown could have been avoided. Effects of scheduling preventive maintenance for non-productive days or shifts with no loss of production. Since some parts are most important to machines. 6. We also need to take into account other effects of unscheduled downtime. the percentage of machine running time continues to increase with the increase of standard preventive maintenance period. such as 1. Initially. all the machines are free and have jus had a preventive maintenance done. For a given breakdown time distribution. you will deal with jobs.5 Summary You need to make decisions at the beginning of each shift regarding maintenance. and 3. 7.

which can be achieved through repair. Maintenance is carried out in anticipation of or in reaction to a failure. to ensure or restore system performance to specified levels.5 Terminal Questions 5. Maintenance covers two aspects of systems – operation and performance. replacement of parts or total replacement of
.6 Answers 5.2 Functions & Feature of Maintenance Engineering 5.4 Summary 5.OM0006-Unit-05-Types of Maintenance Systems
Unit-05-Types of Maintenance Systems Structure: 5.1 Introduction Objectives 5. Maintenance is defined as the restoring of an item to its original condition or to working order.1 Introduction Once the machinery is purchased it must be maintained.3 Types of Maintenance Systems Routine Maintenance Planned /Scheduled / Productive Maintenance Break down or Corrective / Remedial Maintenance Preventive Maintenance Predictive Maintenance Condition Based Maintenance 5.

Improperly performed maintenance or not carried out in time can escalate the problems because of faulty parts running. operational life can be extended. Failure to perform maintenance in time to maintain the availability of the machinery will have serious effects ranging from benign to catastrophic. Maintenance management also aims at developing a reliable and high quality production system. Machineries lose its efficiency after some point of time due to various factors such as wear and tear. based on the practical and economic grounds Maintenance of any kind performed on machinery or equipment is a consequence of the fact that it started deteriorating before failing. Sometimes accelerated testing is used to induce failures and know the behaviour of the systems. Between these alternatives the management decides. Through proper maintenance of these machineries. aging. misuse etc. Developing effective maintenance procedures to restrict such deterioration or failure is vital. Objectives: After studying this unit you shall be able
. Types of maintenance /strategies discussed in this unit are: · Routine Maintenance · Planned Maintenance · Break down Maintenance or Corrective Maintenance · Preventive Maintenance · Predictive Maintenance · Condition Based Maintenance · Total Productivity Maintenance The maintenance plan for a company’s assets can be a combination of the above strategies and could be adopted on the same machine. It is evident that the best maintenance strategy is selected for reducing breakdowns. but there is no guarantee here that the exact nature of defect surfaces.the devices itself. Hence a systematic and structured approach to proper & cost effective maintenance is required. retain the productivity and maintain safe working conditions by reducing the probability of accidents.

scheduling and execution of many maintenance activities. use of robotics and other Computer Integrated systems are developed and deployed for producing high quality products. Flexible manufacturing systems. improved productivity. To offer these requirements. breakdown maintenance or preventive maintenance etc. Such high cost and sophisticated state of art machineries need to operate at optimal levels of performance with high degree of reliability. 5. Maintenance management is entrusted with the total task of keeping the machinery. · · · · · Rapid strides in the advancement of manufacturing technology and its processes with higher powers and speeds. repeatability. Therefore industries have entered into the era of high technology maintenance management to cater to the production requirement of minimum downtime and maximum productivity. high up-time and prolonged mean time between failures (MTBF). high cost CNC machines.
. use of complex processes. rapid traverses. have all warranted the use of sophisticated machineries for production. higher feeds. requirement of high accuracy.2 Functions & Feature of Maintenance Engineering Maintenance Engineering is the function of the production management that is concerned with day-to-day problems of keeping the physical plant in good and acceptable operating condition.. equipment and services in proper working condition that involves planning. etc.· To explain how systems work at their optimum efficiency · To prepare a plan to preserve the value of the assets by different methods · To calculate how to maximize production capability · To prepare a plan and schedule for maintenance work and prevent failures and breakdowns · To Improve quality of products and productivity · To Use of maintenance staff optimally · To Minimize or avoid accidents by periodical inspection and repairs. like repair.

working. lubricating systems. machines. outer cleaning. 5.Malfunctioning of machineries/equipment due to failure to upkeep the operating conditions may result in serious repercussions of reduced capacity. a cyclic operation recurring periodically.1 Routine Maintenance [RM] RM is a procedure followed regularly i. These aspects are to recognized by the maintenance department. lubricate two machines daily] It can be even day to day operational activities to keep the plant running (say: replacement of light bulbs. These include say greasing or lubricating the bearings / systems. It includes activities like inspection. cleaning of machines. RM can be classified as: 1) Running maintenance 2) Shut down maintenance. [say: check all compressors first on Mondays. and equipment by the maintenance staff to preserve such machineries in as near to its original condition as is practical and to realize its normal life expectancy.3 Types of Maintenance Systems A way of reducing the plant breakdowns is to select the best maintenance strategy.e. cleaning. Widely adopted maintenance techniques/strategies are: · Routine Maintenance · Planned Maintenance · Break down Maintenance or Corrective/ Remedial Maintenance · Preventive Maintenance · Predictive Maintenance · Condition Based Maintenance · Total Productivity Maintenance [Discussed in detail in Unit-10] 5. repairing leaks) which include preventive maintenance and forms part of the annual operating budget. Maintenance is the work performed on an asset such as utility. increased production costs. Hence the relationship between availability.
. inspection etc.3. 1) Running maintenance is the work carried out when the equipment or the machine is performing some operations i.e. small repairs. production of low quality products. injury to workmen and finally frequent breakdowns etc may lead to protracted delivery of the product thus inviting customer dissatisfaction. reliability and maintainability of a plant is very important for the maintenance engineers.

lubricate.1. boilers 5. increases productivity as compared to unplanned one and hence it is followed as per the maintenance policy of the company. 5.3.2) Shut down maintenance: certain minor maintenance activities cannot be carried out when the machine is running and hence carried out by shutting down the machine.g.2 Planned / Scheduled / Productive Maintenance Planned maintenance is the activities carried out according to a predetermined schedule and hence known as scheduled maintenance or productive maintenance.3. In this type of service. It involves inspection of all machineries. overhaul. reduces the cost of maintenance.1 Advantages a) Simple to establish & follow b) Little or no clerical work c) High degree of prevention by intercepting developing faults d) A more advanced stage calls for ’service instructions on a pre-printed schedule and checklists’. E. repair and carry out all requisite maintenance before actual break down happens. de-scaling furnaces. thus avoiding a situation of emergency maintenance. the emphasis is on machines: a) What does the manufacturer prescribe? b) Is the unit utilised for two or three shifts per day? c) Is it working under normal load?
.2 Disadvantages a) RM may not provide the service specified by the manufacturer b) May ignore information regarding preceding breakdowns c) Service required for a machine at different frequencies may be ignored d) Similar machines are serviced at same frequency irrespective of usage 5.1.3. Planned maintenance reduces the machine downtime.

2. Corrective maintenance is carried out on all items where the consequences of failure or wearing out are not significant and the cost of corrective maintenance is not greater than preventative maintenance. to bring it back to working order. Unforeseen work is reduced.3.3.1 Characteristics of Planned Maintenance a) Instructions are more detailed than in routine maintenance b) Calls for differently timed service for the same unit c) Schedule is drawn with dates d) Establishes the work-load for the crew e) Entails considerable planning effort. Also called as ‘on-failure maintenance/corrective maintenance’. can be defined as the maintenance which is required when an item has failed or worn out. Planned repair/rectifying the problem is carried out when it is more convenient and cost effective after its failure rather than to disrupt the production with RM. adjustments are shown in overall plan b) Detailed instructions reduce the chance of missing any activity.2.3.3 Break Down or Corrective/ Remedial Maintenance Breakdown Maintenance is the method of operating the machines to run until they fail and then repair in order to restore them to an acceptable condition. c) Provides as much attention on the equipment for the best judgement of the planner [For details on ‘the principles of planning & scheduled maintenance’ refer Unit 6] 5. replacement of parts.
. faithful implementation and recording f) Initial list of planned maintenance will be in detail 5.d) Are the conditions as good as those envisaged by the manufacturer? e) Do we allow for extra attention owing to corrosion-including conditions? 5.2 Advantages of Planned Maintenance Considers all the changes in conditions of use & increased wear of parts a) Inspections.

Corrective maintenance may be programmed.1 Characteristics of Break-down Maintenance System · No services except occasional lubrication unless failure occurs · No maintenance men on regular basis · Maintenance done by sub-contractors · No organised efforts to find out reasons · No stock of spares · No budget · No records · Initially it looks economical · Creates internal problems namely: Who to do the repair? From where to get parts? How do we pay for them? Who will go & buy parts?
.3. On-failure maintenance can be effective if applied correctly.3. Frayed tempers put unnecessary pressures and disturb delivery commitments. misuse or improper maintenance. etc.e. Corrective maintenance activities include both emergency repairs (fire fighting) and preventive (or corrective) repairs. or reconditioning that part to its original or acceptable working condition. The need for repairs can result from normal wear. or where no other strategy will work. 5. Here the machine and the work on that machine stops operating. Repair is restoring an asset by replacing a part which is broken or damaged. involve hazards. This method is expensive in terms of maintenance cost. This system could be called as ‘Operate to Failure (OTP) ’– no predetermined action taken to prevent failure. For example: non-critical low cost equipment. drive shaft broken and hence the transmission fails. vandalism. The above type of repairing and setting the equipment to working condition can be called as corrective maintenance. o Upset schedule resulting in panicky. Ex: electric motor may not start. lost output. i. increased downtime. taken after the failure happens. Repairs are done after the machine fails and hence this becomes a repair work.

preventative maintenance is carried out only on those items where a failure would
.3.3.
5. detection and prevention of incipient failure.4 Disadvantages 1) No warning of failure – safety risk 2) Uncontrolled plant outage – production losses 3) Requires large standby maintenance team 4) Secondary damage – longer repair time 5) Large spares stock requirement 6) Provision of standby plant 5.3.3.3.3.4 Preventive Maintenance PM is a regularly scheduled maintenance activity.5. Preventive maintenance is carried out to prevent an item failing or wearing out by providing systematic inspection.2 Objectives of BD/Corrective Maintenance 1) To put back machinery back to work and minimize production interruptions 2) To control costs of maintenance crew to the minimum 3) To control cost of the operations of repairing 4) To control costs of repair & replacement parts to minimum 5) To control investment cost on purchase of standby or back up machines 6) To carry out appropriate repair intermittently at each malfunction to improve the life of the machine.3. with an objective to anticipate problems and correct them before they occur. In line with management’s policy on obtaining the best value from the maintenance funds.3 Advantages
1) Low cost if correctly applied 2) Requires no advanced planning other than ensuring spares availability 5. This is normally programmed.

. lubrication. checking. clean and up keep To achieve prevention of break-downs planned service is carried out with the explicit additional objective of detecting wear points and ensure perfect functioning by replacing parts Here the safe overhaul interval is selected. -To avoid breakdown & ensure smooth production following time based activities are practiced: 1. 2. PM’s prerequisites are: a) Proper design and installation of equipment b) periodical inspection of plant and machinery to prevent breakdowns c) repetitive servicing and overhaul d) lubricate. Preventive maintenance could be grouped as: 1) Fixed-time Maintenance (FTM) – Here actions carried out at regular intervals (calendar time) e. lifts. sub-station transformers. Routine & planned maintenance includes Preventive maintenance actions. so that the major break downs are avoided & minimizes possibility of unanticipated production interruptions. distribution transformers. Periodic Inspections
. It is much economical to carry out preventive maintenance. etc. Daily Maintenance – Cleaning. 2) Condition-based Maintenance [explained below] 3) Opportunity Maintenance (find out the opportune moment for maintenance) The preventive maintenance is carried out at irregular intervals and this interval is determined by seeing the actual condition of the machine. item replacement. but it is found that a greater number of machine failures are at the peak when machine gets progressively worse over a period say months/ years. Many of these items are also subject to a statutory requirement for inspection and preventive maintenance. repair and major overhaul. fire alarms. isolators. circuit breakers.result in expensive consequences. battery back up at sub-station. etc. e.g.g. electricity supply.

Restoration to recover deterioration 5. Use of recommended Grades of oils 4. More expensive due to more planning &replacement of parts before failing. Reduces unplanned work 6. Increases reliability 3.3.3.4.4. Reduces total maintenance cost 5.3 Requirements of Preventive Maintenance Program 1) Good maintenance management department with experienced personnel 2) To firm up plan of PM in consultation with shop personnel 3) A good lubricating and cleaning schedule 4) Detail procedures on maintenance work 5) Proper records maintained along with manuals.3. parts list etc 6) Adequate stock of spare parts
.1 Preventive Maintenance System is 1. cost estimates etc 2) Use of check lists by maintenance staff and inspectors 3) Identify and allocate well qualified crew & inspectors for making repairs 4) Use of budgeting system for major replacements/ repair 5) Proper procedures laid out for meeting the PM objectives in full 5. Reduces total down time 5. Reduces total work-load 4.3. daily maintenance etc and programming the activities with work content.2 Features of PM 1) Proper identification of items in each machineries which warrants fixed time maintenance.4. 2.

probable causes.a guide showing problems. Higher safety for workers 7. Preparation of history card of all the repair work carried on such a machine and the remarks there on 4.4. Identifying the job to be taken & appropriate case register 2. Preparation of schedule of maintenance 3.4. repair procedures etc 11) Suppliers recommendations for up keep of machineries. Improves productivity due to lesser breakdowns 5. Labor used cost effectively
. Reduction in breakdown frequency 4. 5. Preparation of job specification 5. Maintenance is planned well in advance 2. Preparation of maintenance schedule and detail program of work with time frame for completion 6. Reduction in wear and tear of machines and increase in their life 3.3. Improves reliability of the machineries 6. diagnosis system. Preparation of inspection chart 7.4 Steps involved in Preventive Maintenance 1. Preparation of maintenance report on the work done 8. Feed back on the corrective action/ repair work done and its results 5.7) Properly training maintenance crew Adequate space around machinery for maintenance work 9) Previous data on failure etc of each machine/equipment 10) Systematic approach.3.5 Advantages of Preventive Maintenance 1.

3. Conditions of the machinery can be checked on line periodically or on continuous basis and maintenance crew can take decision & plan overhaul/repair as warranted. Applicable only to age related deterioration 4. corrective maintenance is carried out to repair the equipment after fault occurs/ breakdown happens.3. It is possible to have planned shutdowns and repair 9. 5. Sensitive instruments like vibration analyzer.8. Maintenance sometimes induces failures (infant mortality) 5. Preventive maintenance is designed to prevent or at least to minimize failures/breakdowns and reduce the need for corrective maintenance.7 Differences between Corrective and Preventive Maintenance 1.4.3. amplitude meters. are used to predict ensuing troubles/problems in machineries. Identification of parts and its nature and cost involved in repairs is possible 5. Minimizes breakdowns and hence minimum inventory hold ups 10. Leaser rejection and better quality 11.
. resistance gauges etc. temperatures.6 Disadvantages/limitations 1. 2.4. whereas. sensors for pressure. Less stand by equipment requirement 13. Unnecessary and invasive maintenance is carried out 3. Preventive maintenance program controls the repair costs as well as the overall life of the equipment where as in corrective maintenance brings back to the original life depending on the extent of damage the earier breakdown has brought into the equipment. 12. Less breakdown costs.5 Predictive Maintenance Predictive Maintenance is one of the modern approaches to preventive maintenance where in sensitive instruments are used to predict anticipated failure of machines & equipment. Maintenance activity and costs increased 2. audio gauges.

Under maintenance or too long intervals between two successive checks may result in high incidence of failures. rotor imbalance.e. 1) Similar to health monitoring of senior executives to check symptoms. material and time. health and safety hazards etc) will result in 1) Maximizes the online operations 2) Minimizes downtime 3) Increased plant and Personnel safety 4) Optimal maintenance The above is achieved by continuous plant / equipment monitoring & diagnosing the actual condition by means of online non-destructive testing methods. A major part of the predictive maintenance involves the ongoing analysis to ensure wear levels that damage the machine are within limits Good ability to predict impending failures well in time to prevent breakdowns. incorrect installation.) Measuring of physical parameters may not be enough to detect the destructive effects on a machine or process. Over maintenance or too frequent maintenance increases extensive downtime resulting in added costs on men. maintenance is on a pre-determined cycle whereas in a Predictive Maintenance system maintenance is done only. misalignments. etc. In a Preventive Maintenance system. The intervals should be carefully selected as over maintenance or under maintenance are both detrimental and hence undesirable. pump cavitations. Hence an optimal maintenance interval has to be arrived at. 2) If corrective treatment is not adopted at the right time. analysis and tribology. temperature. oil condition. it may result in serious breakdowns. (which otherwise cause heavy penalty costs. when status or condition so demands It is beneficial to follow a system which is not calendar based but condition based. we should have a continuous knowledge of the machines based on certain critical predetermined / pre-formulated parameters
. which are indicative of malfunctions to decide on corrective treatment. Main difficulty is in making the correct choice of preventive maintenance intervals based on OEM’s recommendations and own -experiences.Predict failures well in advance by monitoring parameters and by use of certain techniques (like vibration. wear debris analysis. i.

there is enough time available for the maintenance crew to make adequate advance preparations. etc. thus making predictive maintenance more economical as compared to preventive and corrective maintenance strategies. smell and through their experience on the existing condition of the equipment/aggregate. FMS with artificial intelligent devices and computer simulations and modeling. With rapid developments in machining technology through CNC controlled machines.A given machine can continue to be kept in operation as long as the monitored parameters continue to remain within the laid down limits. It is just like a hammer used to strike a wheel to listen for that distinctive sound to say whether there is crack in wheel rim or not. Predictive Maintenance is very cost effective where cost of unplanned breakdowns is very high. When permissible limits are reached and warning signals are issued by the measuring devices. Temperature changes can be photographed
. 5.3. A sense of confidence is created amongst production and maintenance personnel when they analyze the monitored data and predict that the machines are operated safely till they reach maximum permissible limits. Condition monitoring is merely a tool that is used by crew through touch. if practiced effectively. but much before the possible breakdown. CBM involves recording some measurement that gives an indication of the condition (ex: increase in vibration levels. An ability to forecast the machine behavior by Condition Monitoring is a pre-requisite for Predictive Maintenance Operators who work with equipment every day can listen to equipment and identify changes in noise levels and vibrations. increased leakages etc) CBM is a continuous or periodic measurement and interpretation of data to indicate the condition of an item to determine the need for maintenance. temperature soars. can save around 30% of maintenance costs and with a bonus of 15% savings in energy costs. The main function of condition monitoring is to provide the knowledge of a machine and its rate of change. Between the ‘action limit and the maximum permissible time limit’. more universal and better predictive tools and instruments are added in the system. In the Condition based maintenance (also known as Dynamic predictive maintenance or Diagnostic maintenance) the plant is maintained just after some problems arisen. Predictive Maintenance. to cut downtime. it implies that the particular part needs replacement and a special attention.6 Condition Based Maintenance CBM relies on the fact that the majority of failures do not occur instantaneously but develops over a period of time.

An investigation can then be carried out to identify the exact problem. CNC systems have built – in diagnostics which continuously monitor the system hardware to ensure normal functioning. unbalance in rotors.1 Condition Monitoring Methods There are two methods used namely: 1. which gives warning that something is ‘not right’. This type of maintenance check on performance is vital as the future failures in safety systems can have more catastrophic effects. corrosion Audible – Unusual noise. etc. which are to be controlled by maintenance a) Vibration Sensors – to track tool wear/ breakages. Curve when extrapolated can indicate maximum & safe permissible limits 5.6. Action limit curve shows the prescribed for monitoring parameters during normal operations. contaminated cutting fluid Touch – Excessive bearing temperature State-of-the-art CNC systems facilitates adaptive Controls with signals from appropriate transducers. Trend Monitoring. are displayed on the screen well in time to facilitate corrective action without disruption of production. misalignments. if other parts of the system fail. overheating of motors c) Current sensors – cutting load monitored by sensing spindle Condition Monitoring is achieved by the operator’s senses to detect abnormalities Visual – Leakages. Chatter Smell – Smoke.3. Indications like over – temperature.through IR thermograph. gear defects. Condition monitoring is dependent on sensors and transducers for measuring different parameters. Condition Checking & Monitoring a) Trend Monitoring:
. low battery voltage. mechanical looseness b) Thermostats – hydraulic oil temperature. 2. alarms.

c) Condition Monitoring: Includes three stages: 1. Detection (when) of the developing fault at an early stage 2. proximity probes) to record vibration level 3) Wear Debris monitoring: This works on the principle that the working surfaces of a machine are washed by the lubricating oil and any damage is detected from particles of wear debris in the oil. b) Condition Checking: Condition checking is where a check measurement is taken with the machine running. to monitor the rates of internal corrosion of the wall of the plant. · Reduces the cost of maintenance · Capital invested can be recovered faster. 4) Performance and behavior monitoring: Involves checking the performance of a machine to see whether it is behaving correctly. d) Economics of Condition Monitoring: The savings. using some suitable indicator & is used as a measure of machine condition at that time. which can be made by the application of CM: · Avoiding losses of output due to breakdown of machinery. Diagnosis (what) of its origin so that spare parts can be ordered 3. Prognosis (forecast) subsequent measurement which will then establish the trend and enable the repair schedule to be planned. This may be done by
. accelerometer.Trend monitoring is the continuous monitoring or regular measurement and interpretation of data collected during machine operation. 2) Vibration Monitoring: Involves the attachment of a transducer (velocity. e) Selecting Methods of monitoring Five main techniques of conditioning monitoring 1) Visual monitoring: inspection & recording of surface appearance. to indicate variations in the conditions of the machine or its components. 5) Corrosion monitoring: Is applied to fixed plant containing aggressive materials.

Training examiners for the above jobs. 5.2 Implementation of Condition Based Maintenance: Involves: 1. Some forms of inspection utilising human senses can be inexpensive 3. Labour can be organised 8. standby availability of machine. 5. 7. contamination etc) to be measured. Establish for each part of the machine the severity limits of the machine condition parameter (Vibration. 7. failure statistics (MTBF-MTTR).3. Maximises equipment availability 2. Selecting critical machines for CM 3. standardizations planned. Select proper examining technique. Recording data 8.3. 5. 6. The hole is then plugged with a suitable leak proof material. Cost of examination. cost of maintenance. To arrive at best interval for examination considering the criticality of process. Allows shutdown before severe damage occurs 4. Establishing programs and methods specifying the parts to be examined 4.6. Production can be modified to extend unit life 5.3 Advantages 1.4 Disadvantages 1) Thermograph & Oil Debris Analysis [specialised equipment and training]
. Maintenance can be planned. overall cost of failure.3. Listing and numbering of machine to have identification and location details 2.6.6.drilling a hole through the wall and drilled coupon of material is observed for corrosion. Cause of failure can be analysed 6. Spares can be assembled 5. operating conditions. sound.

fixtures and tools d) All the above 2) Which of the following is not an objective of remedial maintenance? a) To put back machinery back to work and minimize production interruptions b) To control costs of maintenance crew to the minimum c) To control cost of the operations of repairing d) Replacing the faulty machine when it starts malfunctioning.e.2) Requires careful choice of the correct technique. e) To control costs of repair & replacement parts to minimum f) To carry out appropriate repair intermittently at each malfunction to improve the life of the machine. 3) Time is required for trends to develop to know machine condition Self Assessment Questions 1) Which of the following is not a common cause of equipment breakdowns? a) Improper preventive maintenance b) Inadequate lubrication c) Improper setups of jigs. a _______________ recurring periodically 5) In the following list find out which one is considered as disadvantage of routine management:
. 3) Irregular preventive maintenance do not include a) Repairs b) Overhauls c) Reduction of noise levels and vibrations d) Clean up of leakages etc on all the machine aggregates daily 4) RM is a procedure followed regularly i.

No services except occasional lubrication unless failure occurs 2. No stock of spares 6. ______________________ 5. 6) Planned maintenance is the activities carried out according to a ______________ and hence known as scheduled maintenance or productive maintenance 7) Characteristics of Planned Maintenance-fill up the missing one: 1) Instructions are more detailed than in routine maintenance 2) Calls for differently timed service for the same unit 3) Schedule is drawn with dates 4) ___________________________ 5) Entails considerable planning effort. 9) Characteristics of Break-down Maintenance System-fill the missing one: 1. Initially it looks economical
. faithful implementation and recording 6) Initial list of planned maintenance will be in detail Breakdown Maintenance is the method of operating the machines to run ______________ and then repair in order to restore them to an acceptable condition.1) Simple to establish & follow 2) Little or no clerical work 3) High degree of prevention by intercepting developing faults 4) RM may not provide the service specified by the manufacturer 5) A more advanced stage calls for ’service instructions on a pre-printed schedule and checklists’. Maintenance done by sub-contractors 4. No maintenance men on regular basis 3.

with JIT inventory and sophisticated processes.7. 2.4 Summary Poorly maintained machines/equipment has severe negative impact on the productivity and the quality of the output in a production unit. and predictive. CBM involves recording some ___________ that gives an indication of the condition. Predictive maintenance is a type in which the vital attributes of a system are monitored continuously and any deviations from the accepted limits are taken to rectify the problem. Use of recommended Grades of oils 5. 2) ____________________ 5. In the present high tech production. 13) There are two methods used namely-Which is the second one 1) Trend Monitoring. Maintenance is of three main categories: breakdown. Daily Maintenance – Cleaning. Preventive maintenance is undertaken before need for maintenance arises and aims at minimizing the anticipated breakdowns. In planning. maintenance managers have to decide on a proper balance between preventive. Creates internal problems namely: Who to do the repair? From where to get parts? How do we pay for them? Who will go & buy parts? 10) To avoid breakdown & ensure smooth production following time based activities are practiced. preventive. lubrication. any stoppage due to breakdown in any part of the system will affect the entire production process. checking. predictive and remedial maintenance.
. Breakdown or remedial maintenance is undertaken when a machine breaks down or malfunctions.which one is not the recommended practice? 1. etc. Restoration to recover deterioration 11) Predictive Maintenance is one of the modern approaches to preventive maintenance where in __________ are used to predict ____________ of machines & equipment. Periodic Inspections 3. maintenance has been given more importance in the operational plans. using high technology machines. Check all the machines at firmed up time intervals 4. To counter this. 12) CBM relies on the fact that the majority of failures do not occur instantaneously but develops over a period of time.

What is predictive maintenance? What are its advantages over preventive maintenance? 13. What is meant by planned/scheduled/productive maintenance and what emphasis it pays in maintaining the machine/equipment 4. 14.In the Condition based maintenance (also known as Dynamic predictive maintenance or Diagnostic maintenance) the plant is maintained just after some problems arisen. Describe the procedures of preventive maintenance program 10. What are the advantages & disadvantages of breakdown/corrective maintenance? 8. Organizations have realized the importance of maintenance and its planning. What are the advantages of Planned Maintenance? 6. Where this type is applicable. Define preventive maintenance and state its objectives 9. but much before the possible breakdown. Explain briefly the condition based monitoring methods 15. What are the advantages and disadvantages of condition based maintenance? 5. Total productivity maintenance is practiced to improve the productivity of the equipment by minimizing the number of breakdowns and malfunctions. State the objectives of maintenance management? 2. accidents and minimizing the costs of maintenance activities? 5.6 Answers
. What are the important functions of maintenance department 5. CBM is a continuous or periodic measurement and interpretation of data to indicate the condition of an item to determine the need for maintenance. Which enables them to reduce breakdowns. Discuss the advantages and limitations of preventive maintenance 11.5 Terminal Questions 1. Distinguish between preventive and breakdown maintenance 12. What are the characteristics & objectives of breakdown/corrective maintenance? 7. What is condition based maintenance. Outline the various types of maintenance 3.

as they leverage their expertise into job plans. Here procedure already in the file or important information that persons who worked on that equipment have recorded previously. If detailed procedures and checklists contribute to better reliability. but certainly brings together many aspects of maintenance. storeroom support. tool room facilities. Objectives: After studying this unit you shall be able to · Prepare a plan for maintenance · Analyse the benefits of planning for maintenance · Examine the principles of maintenance planning
. planning is very essential. control of inventories. Other tools used are work order system. planners. data collection and research of certain processes etc. are the subjects being discussion. Planning and scheduling promotes labor productivity by examining potential delays and scheduling work. and safety. communication.All manufacturing units having varieties of machineries and equipments require maintenance to keep them up in good working conditions and for sustaining and achieving higher productivity. The final improvement to over 50% can be achieved through special aids. engineers. Planning does not solve everything. it is preferred for the organization to become a procedure-based one with teams of experienced technicians. qualified personnel. To achieve the desired maintenance efficiency. shops. leadership. and project maintenance is essential. tools. tool rooms. organizations could improve maintenance productivity to about 40%. and other vendors to cater to the common maintenance tasks on critical equipment and safety equipment. predictive maintenance. Where does planning fit into? What principles make it work? How planning is required to be done? How to provide additional resources for planners and personnel for maintenance activities? Etc. By implementing fundamental planning and scheduling system. The planner should also give more attention to critical equipment and safety areas. and maintenance measurement. The planning system is designed with procedures to be followed over time through a systematic job plans. The plant has better control over work that is scheduled. management. performance. teamwork. Planning concentrates on adding value. consideration of reliability maintenance as preventive maintenance. are included in the job plans. In addition.

The work plan includes a job scope. 6. · Planner does preparatory planning for the crew supervisor and craft persons who executes the work. · The planned information gives the supervisors a reference for expected work and time for completion and helps to have a control through on problems that might lessen productivity. and labor time estimate. · The planner identifies appropriate materials for the specified job and checks whether they are available or be specially obtained. · Once the work order is received. For this the maintenance planning will have the following functions: · Coordinating mechanism within the maintenance department. The work plan is nothing but the information a planner makes ready for the technician to execute the work. identification of craft skill required. thus enabling a better control over their work.3 Planning Vision & Mission The mission of planning revolves around doing the right jobs that are ready to go. To prepare a job in advance.· Distinguish between preventive and breakdown maintenance planning. procedure for accomplishing task and identify any parts and special tools required. · The time estimates made by planner gives the idea to crew personnel to judge how much work is assigned and what work is there. · The planner considers the proper scope of work for the job. Coordinating function is the key to achieve competitive edge. · Maintenance planning brings together or coordinates the effort of many other aspects of maintenance. For ex: Planner has to judge whether the defective valve should be repaired or replaced.2 Functions of Maintenance Planning Maintenance management uses planning as a tool to reduce unnecessary job delays through advance preparation. a planner develops a work plan after receiving a work request. · The planner specifies appropriate craft skills required for that particular job. the maintenance planning initiates action. · Crew personnel are then assigned the job for execution and avoid problems such as delays stemming by insufficient skills/ not having required materials or tools.
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without wasting time. and it controls and coordinates and brings resources to leverage productivity. The entire maintenance organization should be committed to schedule proactive works. 7) If parts are not in the inventory. planning sets the stage for the maintenance force to act upon quickly. It also involves identifying the actual work scope. With proper planning or preparation efforts for each job. and allow advance scheduling through which the supervisors will assign and control the proper amount of work. seals. work involved. 4) Planners evolve good planning methodology that increases maintenance productivity. 6. A planning mission statement is: “To increase the Maintenance crew’s ability to complete the work orders quickly”. 2) The planner writes work instructions on how to do the job. 6) The planner reserves such required parts in the store to ensure their availability. bearings etc) along with their identification numbers. Arrange parts required to be placed in a convenient location nearer to the job site before the job starts. arrangements are ready.4 Functions of Maintenance Planner 1) Maintenance planning involves identifying parts and tools that are necessary for maintenance jobs. method of maintenance. crew schedules. Work plans avoid anticipated delays. 9) Planner provide a bill of materials or an illustrated parts diagram both to the stores person and craft men. so that technicians need not wait for parts to arrive. 3) With preparatory work. release of the work orders to proceed etc.
. Doing the right jobs involves job priorities. parts. considering the safety aspects of the job. but ready handle judiciously the reactive type of work also. for easy understanding and identifying the proper parts for his next work. Planning is Information central. clearances. improve on past jobs. tools.The planning mission states “Doing the right jobs & ready to go”. A work crew is ready to go immediately to scheduled work assignments as all instructions. 5) The planner writes a job plan that identifies parts needed (such as gaskets. planner initiate action to organize and get them. crew starts their work as per job.

5 Benefit of Planning As planning consists of arranging parts and the necessary tools for maintenance work and provide necessary guidelines by use all the inputs effectively through a maintenance system. craft and skill level required.7 How Much Planning Will Help? a) Tangible Help:
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Planning provides tangible help for organization to achieve:
. specify job scope. 4) Skill levels and time estimates on jobs and proper scheduling are included in the subject work order. 2) Planner plans work order.6 Planning System In a proper planning system. 6. with identification numbers. anticipated parts & tools. time estimates. fork lifts. 3) Planner evolves a system and procedure for each type of maintenance work. resulting benefit achieved are the improved productivity and overall effectiveness or efficiency in maintenance. Hence the purpose of planning is to focus on high productivity through an organized planning & scheduling principles.10) Planner is required to coordinate with vendors & ensure material supply along with the quality control on vendor supplies. pallets etc for easy movement of identified parts and tools to work site in advance. 6) Establishes through work order system. the maintenance process has the following steps: 1) Receives request from the concerned section for the maintenance work. 11) Planner identifies special tools needed by the craft man for maintenance activities and reserve such tooling and other accessories at the place of work. 7) Prepares Schedules for maintenance works and follow track until complete. 5) Creates data and information on machineries and equipment and its maintenance methodology for future reference and analysis. 6. 12) Planner will arrange material handling equipments like crane. Institute a control system that contributes to managing productivity. procedures for assigning proper amount of work to all the skilled/unskilled crews. 6.

The practical result of planning-example:
In a power station. also known as wrench time.8 Productivity. thus using the freed 10 trained personnel for other productivity improvement activities.
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Through proper planning. Analysis of the nonproductive time is one of the most valuable work-sampling.-Amount of work accomplished rises. c) “World class” wrench time · Statistical work sampling studies measures productive time. 6. -Work force is freed up. b) Improving the Wrench Time and Productivity · Work activities are classified differently. Improvement here was only possible with the planning in place. could achieve a remarkable reliable plant capacity within a year through superior availability and a drastic improvement in work force productivity. -Extra labor power can be reallocated to added value activities. where the management created an exclusive planning group. intangible benefits of planning were seen in providing a better control of maintenance work. But it proved the other way as seen from the above examples. The industry’s average productive maintenance time was less than 30% (the measure of wrench time) when a typical maintenance technician has spent less than 20% on the real work and it is found that the balance time is spent on other nonproductive tasks. Specialization & Coordination of Planning a) The specific benefit of planning in Wrench time improvements · There are organizations who feel that the planning work is part and parcel of the maintenance crew. Crew will plan their work and then executes. one can calculate and measure the actual amount of increased maintenance productivity. thus frees technicians for more productive work. To determine if any of the delay time could be avoidable requires planner’s assistance for analyzing such nonproductive time. Further if there are three crews working with
. Practically the total maintenance work was completed by 35 personnel as compared to previous year’s statistics of using around 45 personnel for the same output. · The maximum performance target for wrench time was shown at an average of around 55%. where in the planning addresses and reduces delays. In addition. Is this wrench time a reality? Instances are there in which experienced workforce moved from average 35% wrench time to 55% with fine tuned planning.

which spells the importance of planning jobs for maintenance. There is a methodology of work measurement what is commonly known as wrench time and this frequently misunderstood principle and hence must be made clear to everyone concerned. 3) Planners base their files on the component level of systems. recognizing skill of the craftsman and measuring performance must be understood by every one concerned with production. But experience has shown that a single planner can plan maintenance jobs for more than 20 persons. These principles must be understood by all concerned to have effective planning process. for which they train and maintain separate groups of mechanics. then total productivity is 100 % [2x 50% +0= 100%. 1) Company organizes planners into a separate department. the other two crew reached a wrench time of 50%. which is essential for a competitive edge. as compared to 3x30=90%]. 4) Planner expertise dictates job estimates. 6. Each principle identifies important crossroads. Six principles greatly contribute to the overall success of planning. and if one is allocated to planning job and with whose instance. and instrument technicians. Industry to this day continues to use specialization. Decisions making at each crossroads on the alternative ways to conduct planning and execute is essential and ultimate success of planning depends on this situational oriented decision.wrench time of 30%. 5) Planners recognize the skill of the crafts. Loading these specialists to achieve higher wrench times also requires a sound planning and proper coordination. 2) Planners concentrate on future work. b) Specialization and Productivity: · Experienced crew are specializing in a particular field and achieving the specified goals. Specialization increases productivity per person.9 Maintenance Planning Principles The principles or paradigms that are evolved over the maintenance mission will profoundly affect planning.
. electricians. The principles of having planning as a separate department in order to focus on the future work and consequent use of planner’s expertise to create estimates.

or other helpful information so that future work plans and schedules might be improved. Principle 1: [The Company organizes planners into a separate department] · The planners are organized into a separate department from craft maintenance crews to facilitate specialization in planning and focus on future work. plan changes. Principle 3: [Component Level Files] · Planning maintains a simple. The file system enables planners to utilize equipment data and information and their experience on previous work to prepare and improve work plans. especially on repetitive maintenance tasks. The planners ensure that the feedback information is properly filed to aid future work. which helps planners to become specialized in all the tools and techniques of planning · Planners need to work closely to ensure proper execution of work with consistency. The Planning Department concentrates on future work and provide the crew to plan their work in advance and remove backlogs · After job completion. Matching identify tags on the machineries are also arranged. · Because planning contributes to scheduling. secure file system based on equipment tag numbers. · The planners must be engaged in preparing work that has not yet begun. The feedback consists of any problems. feedback is given by the lead technician or supervisor to the Planning Department. · Planners use personal experience and develop work plans to avoid anticipated work delays and quality or safety problems.6) Work sampling of direct work time provide measure of planning effectiveness. The supervisor has an obligation to complete the assigned work in an expeditious manner with a minimum of interruptions · The crew focuses exclusively on executing assigned work. · Planners report to a different supervisor/ lead planner who will be responsible to provide direction and ensure consistency within the planning group. Principle 2: [Focus on Future Work] · The vision of planning is to increase labor productivity by preparing the jobs in advance. the lack of planning effort may decrease the number of work assignments to crew members · The company organizing planners to a separate group.
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The planner’s responsibility is to firm up the scope of the work request including clarification of the originator’s intent wherever necessary. · The planner then plans the general strategy of the work (such as repair or replace) and includes procedure if it is not already there in the file. · Routine maintenance offers the highest potential for planner contribution to company success because more intricate or unusual maintenance tasks receives necessary help from plant engineering department Principle 5: [Recognize the Skill of the Crafts] · The Planning Department recognizes the skill of the crafts. · Supervisors and plant engineers are trained to access these files to gather information they need with minimal planner assistance. · Plant must choose from among its best craft persons to be planners. · Supervisors must train technicians with deficient skills and give proper support and guidance · Technicians must execute the job precisely as planned for three reasons. File cost information assists in making repair or replace decisions.· The majority of maintenance tasks are repetitive over a period of time. The planners also use their own expertise to formalize best practices on individual job plans. Any recommended deviations from the job plan must be approved by planning before execution. The plan dictates the skill set necessary to accomplish the work given the state of the job plan. These planners rely greatly upon their personal skill and experience in addition to existing information in the files to develop job plans. · Planners give information to supervisor for scheduling control. Principle 4: [Estimates Based on Planner Expertise] · Planners use personal experience and file information to develop work plans to avoid anticipated work delays after considering quality and safety problems. · Craft technicians use their expertise to make the specified repair or replacement.
. The planner calls for a minimum craft skill on a job plan. · This principle dictates that planners depend on the workforce being sufficiently skilled when he is putting a minimum level of detail into the initial job plans. The planners and technicians work together over repeated jobs to develop better procedures and checklists.

Principle 6: [Measure Performance with Work Sampling] · Wrench time is the primary measure of workforce efficiency and of planning and scheduling effectiveness. clearance. parts. statistical observational techniques & study. The time that employees spend at their job sites working is called direct or productive work. coordination with other crafts. These reduce the incidence of reactive maintenance work and to increase plant reliability. This determines the effectiveness of the maintenance planning program. and project work and their relationship to the development of the planning principles and practices are discussed here. · Measuring wrench time thus gives an overall indication of how well the other principles have been implemented or accepted. the planning system counts on the skilled technicians giving feedback on job plans so that their expertise and the planner’s expertise both contribute to adding information to future plans. Wrench time is the proportion of available time-to-work time during which the craft technicians are on productive working on a job site. tools. travel.10 Planning Preventive & Predictive Maintenance. or equipment information are all deducted. · Principle 6 dictates that measuring how much time craft technicians actually spend on their job site versus other activities performed such as obtaining parts or tools. Wrench time is measured accurately with a properly structured. Starting with a basic system. planners visualize the types of work orders to be released for preventive maintenance tasks for the next week. not the control of planning or the work force. a) Preventive Maintenance [PM] and Planning · The planning department studies and issues PM’s schedules and reviews them periodically.
.· Finally. Delays such as waiting for assignment. 6. predictive maintenance. Projects The concepts and importance of preventive maintenance. This principle holds that delays in technician’s job should be avoided. · Work sampling to determine wrench time gives this measure of how much planning is helping in the process. Wrench time analysis is an indicator. What is actually important is the analysis of the nonproductive time. Planning can adopt preferred maintenance for higher effectiveness. instructions.

· A planner should plan each of the PMs with scope and craft requirements such as numbers of persons. as improper lubrication leads to total damage to equipment. work hours. The plan should also list anticipated parts and special tools. or minor repairs. · Lubrication is important part of a PM program. and duration. · The planner should allow some extra time in the work order on all PM work for making unspecified excessive cleaning. · PM plans should specify torque requirements or attach torque charts where appropriate and include torque wrenches as a special tool. The dirt and grime also add undesirable insulation conditions that may affect equipment performance. For this. Lubrication. repairs. For ex: tightening of fasteners in the coupling if he found they are loose. · Cleanliness helps reduce contamination sources and such clean surfaces to reveal the presence of new leaks. the technician is empowered to make any minor equipment adjustments or minor repairs during execution of the PM. · This requirement of corrective maintenance is ‘TLC’ i. Many do value assigning with experienced personnel to perform PM work orders. PM plans can include rags for wiping and removing old grease when parts are dissembled. · Emphasis in all PMs is to inspect the equipment for abnormal situations.
. which are contributing to more than 50% of all breakdowns. · The planner must receive feedback to improve the PM work order itself. Predictive maintenance (PdM) uses technology not available to the regular maintenance work force. PdM personnel make the call on the creation of new work orders. lubrications etc. and Cleanliness. · PdM technology greatly moves the plant’s reliability upward as the predictions in predictive maintenance show an important capacity for growth in accuracy. Tightness. tightening of bolts. Planning for parts encourages the replacement of fasteners based on the technician’s decisions. small adjustments.e. · The scope should extend beyond simple repair and replacement of parts to improve equipment reliability as well. · Planners should also review the histories and feedback from all work orders to determine if additional PM work orders are needed. b) Predictive Maintenance [PdM] and Planning · Planning plans and schedules PdM work orders. on the work done.

Each principle resolves a crossroads decision that affects the planning effort. The decision the company makes regarding each situation determines the ultimate success of planning. or other rebuild tolerances. with active participation and assistance from the planning group.
. planning group plans and schedules work orders to implement projects as regular jobs.· Planners must accept PdM work orders for jobs and translate them into the appropriate scope for the maintenance crews. · Planners should facilitate PdM when work on equipment is in process. · Planners should insist to utilize standards set by PdM for certain jobs. · Planners should insist that PdM uses the same equipment tag numbers for ease communication problems. · Planners must vigorously pursue collecting documentation to establish files and also overview position regarding the project replacement or overhaul. · Plant normally has the personnel to implement such maintenance project work with the productivity prescribed in the planning and scheduling system. The planning effort has mainly focused on making individual jobs ready to go by identifying and planning around potential delays. Consideration of six basic principles greatly boosts the planning program efforts toward success. 6. bearing clearances. · The PdM group can update the technology of the maintenance force. c) Project Work and Planning · Similar to PdM. · Planners should be able to estimate and commit the project schedules with plant engineering and scheduler assistance. Plants treat projects as outages and planned as long-range scheduling. The application of maintenance planning makes possible the dramatic improvement in maintenance productivity. the company has to make a decision regarding alternate ways to conduct planning. so that PdM personnel may quickly climb the learning curve. At each crossroads. but difference is in the larger nature of projects. which involves alignment criteria.11 Summary of Maintenance Planning Effective maintenance is vital to provide reliable plant capacity.

efficiently. recognizing the skill of the crafts. The principles used for planning and scheduling are for achieving the forecasted skill levels. and then measure schedule compliances. Planners need to focus on future work not yet begun.The principle of having planning as a separate department. allowing the crew supervisor to handle day’s work. The analysis revealed that the large delay times not only for parts.
. Planners need to avoid continually being interrupted to resolve problems for jobs already under way. The planned work packages increases the maintenance department’s ability to complete work orders effectively. Wrench time will measure whether the objectives of planning are met or not in reducing job delays. 6. utilize files. the principles or paradigms in order to evolve effective scheduling will come through effective planning process. using planner expertise to create estimates. Plnners must possess the experience of top level technicians in order to scope jobs. The crews worked on the planned jobs and work sampling study made on it indicated a wrench time of 25% only and further plant could do better job if improved upon. Because most jobs are repetitive. and safely. and estimate times adequately. file history help technicians to avoid previously faced problems. parts availability problems or not properly planning issues Companies placed an emphasis on planning and also they doubled the parts availability in stores to reduce ordering needs. the schedules and job priorities for every forecasted work available. or travel categories. having component level files. break. This aligning of the work to accomplish the desired effective and efficient maintenance led to the principles of scheduling. lunch. but also exists for excessive startup.12 Maintenance Scheduling Principles Scheduling principles envisages the vision. which is discussed below. They solved the problems by addressing symptomatic of tools. instructions. the technicians would scope out the jobs with their social & other times. gave a clear picture of how technicians are completing their work. are all in the total system. focusing on future work. When work orders are received. Maintenance needed certain methodology to assigning enough work through the planning process. and shutdown Wrench time concept of measuring the work for each hour of the day. tools. and measuring planning performance with work sampling for technician’s direct work time. Only when planning keeps a separate file for each piece of equipment. it is practical to retrieve information when needed. .

Plant priority plays a larger role in creating the schedule of work and all involved should treat it as a serious matter. Planners plan the jobs for lowest required skill levels. as they create a framework for successful scheduling of planned work. Crew supervisors forecast available work hours one week ahead by the highest skills available. 6. Each principle sets guidelines on how the maintenance should handle different scheduling process. · The priority may be reviewed periodically and adjusted in coordination with crew. Principle 2 [Entire plant respect the importance of schedules and job priorities] · Weekly and daily schedules must be adhered to by the crew as per the priorities mentioned in the work orders to prevent undue interruption in schedules. The entire plant must respect the importance of schedules and job priorities.Routine maintenance needs the use of principles. and job duration. 2. The appropriate priority for the work is based on established plant guidelines. if required while assigning individuals to execute job plan. Schedule compliance of wrench time. 3. lowest required craft skill level. planners and the plant manager. § Job plans provide information about the number of persons required. · Advance scheduling of enough work for the entire week sets the goal for maximum utilization of the available craft hours. 5. It also ensures that a sufficient and the right work are assigned.
.13 Six Maintenance Scheduling Principles Six principles that greatly contribute to the overall success of scheduling are: 1. Principle 1: [Planners plan the jobs for lowest required skill levels] § Essential part of Principle 1 is that job plans identify the lowest skill necessary to complete the work with the contention that the supervisor will have higher skill capability also. Schedule assigns planned work for every forecasted work hour available. craft work hours per level. 4. Does the job require mechanics or machinists? Does the job require three helpers to assist a certified electrician? Etc that are necessary for advance scheduling. provides the measure of scheduling effectiveness. Crew supervisor matches personnel skills and tasks 6.

· Crew supervisor matches personnel skills and tasks. · First two principles are the prerequisites of the principle-3 scheduling · Scheduler selects the week’s worth of work from the overall plant backlog. · Consideration is also given to multiple jobs on the same equipment or system and of proactive versus reactive work available. Principle 3 [Develops week’s schedule for each crew & craft hours required] · Develops a week’s schedule for each crew based on craft hours required. It allows for emergencies/high priority/ reactive jobs by scheduling sufficient amount of work hours. after considering the tasks that are being interrupted · Principle 4 brings all the three previous scheduling principles together. · Preference is given to completing the higher priority work by utilizing whatever skills available than working on completing the lower priority work. job priorities. crew work load is 1000 worthy labour hours. · Scheduler assigns work plans for the crew to execute during the following week for 100% of the forecasted hours i.e. · Scheduling plan is for performing all the works available in the system.
. and reactive jobs as a guide. As these may cause unique problems it is better to be avoided. forecast of highest skill. Principle 4: [A week’s schedule will assign work for all the available work hour] · A week’s schedule will assign work for the total work hours.· Inefficiency peeps through the interruption by low priority jobs coming in way of urgent jobs progressing. · Scheduler uses a forecast of maximum capabilities of the crew for coming week. If a true emergency arises. it is better to delay identified job in full rather than completing half. and information from job plans. This includes proactive work. · Scheduler also uses job priority and job plan information. Principle 5: [The crew supervisor matches personnel skills and tasks] · Crew supervisor develops a daily schedule one day in advance using current job progress. new high priority. · Over assigning and under assigning work are common and acceptable in industries.

allow crew supervisors to make daily schedules. When setting craft and time requirements. Six basic principles form the foundation of successful scheduling and make schedules and priority systems important. · Planning individual jobs can reduce delays such as waiting to obtain certain parts. Work sampling or wrench time is the best measure of scheduling performance. 6. Adhering to schedules is important as interrupting jobs leads to overall inefficiency. it relatively balances by week end. crew supervisor is the best judge to create the daily crew work schedule. · Each day the crew supervisor assigns the next day’s work to each technician. Maintenance dept also tracks schedule compliance. job plans must plan for the lowest required skill level. In case of delay in actual job progress and the incidence of unexpected reactive work in place. This increases flexibility in choosing jobs. The priority system must properly identify the right jobs to start. Knowing of the lowest skills required for jobs and the highest skills available allows developing a schedule with proper work for the week. scheduler to develop schedule in advance.· Crew supervisor handles the current day’s work and any other problems in emergency maintenance · Although individual jobs show a wide variance between planned and actual times.14 Summary of Maintenance Scheduling Maintenance management must consider main scheduling in the maintenance planning strategy to avoid problems of improved efficiency. Work sampling or wrench time studies quantify delays & gives measures of planning and scheduling effectiveness. tools. · Schedule compliance is the measure of adherence to the one week schedule and its effectiveness.
. assigns work for all available labour hours. He will ensure that each technician receives assignments totalling to full day’s work Principle 6: [Wrench time is the primary measure of workforce efficiency] · Wrench time is the primary measure of workforce efficiency and of planning and scheduling effectiveness. or technician instructions · Scheduling aims at reducing delays. and track schedule compliance.

Hence use of planned and scheduled work packages increases the maintenance department’s ability to complete work orders effectively. and works such as preventive maintenance/ breakdown work and release of the work orders to proceed. This involves job priorities. The planners and crew had to deal differently with urgent reactive work by developing job plans for reactive work. A planning mission statement may be: ………………………………….. · A maintenance planner does preparatory planning for the craft persons · The planner identifies appropriate materials for the specified job and checks whether they are available or must be specially obtained. In the maintenance process given below which one not the step to be considered. and safely. Principles 3 through 5 establish basis of scheduling process. crew schedules. through advance preparation. Self Assessment Questions 1. efficiently. Further working to the maintenance planning based on the six planning principles along with the six scheduling principles will help improve the productivity.
. 5. 2. · Crew personnel are assigned the job for execution · The time estimates are made by planner · Maintenance planning brings together or coordinates the effort of many other aspects of maintenance. 3. · To arrest the leakages and keep up the lubrication system · The planner specifies the appropriate craft skills required for that particular job. 4. To prepare a job in advance. The planning mission statement could be ……………………………. Principle 6 sets overall indicators for scheduling control. a planner develops a …………… after receiving a work request.Schedule based on the wrench time has to be practiced. which one is not relevant? · Coordinating mechanism within the maintenance department.. Principles 1 and 2 are prerequisites for scheduling. Out of the maintenance planning functions. Maintenance management uses planning as a tool to reduce …………………. .

Statistical work sampling studies measures ……………. Which is sixth one? a) The company organizes planners into a separate department. .. b) A planner plans the work order by specifying job scope. c) Planners base their files on the component level of systems. b) The work force is freed up. time estimates. procedures for assigning proper amount of work to all the skilled/unskilled crews h) Prepares Schedules for the maintenance works and follow track until complete. with all their identification numbers. g) He establishes through work order system. craft and skill level required. c) ……………………………………………… 7. Specialization increases ………………………. d) Planner expertise dictates job estimates.
. c) Planner evolves a system and procedure for each type of maintenance work d) Skill levels and time estimates on jobs and proper scheduling are included in the subject work order. as well as specifying anticipated parts and tools. per person 9. Six principles greatly contribute to overall success of planning. Fill in (c) below: a) The amount of work accomplished rises. e) Fix up the wages for each of the work based on the skill level f) Creates data and information on all machineries and equipment and its maintenance methodology for future reference and analysis. also known as wrench time. 8. b) Planners concentrate on future work. Planning provides tangible help.a) Receives request from the concerned section for the maintenance work.work time during which the craft technicians are on productive working on a job site. Wrench time is the primary measure …………………………………………… Wrench time is the proportion of available time to. 6.

six principles that greatly contribute to the overall success of scheduling are discussed below. a. predictive maintenance. 10. ………. e.. d. and then measure schedule compliances 15. upward as the predictions involved in predictive maintenance show an important capacity for growth in accuracy. What are the benefits of maintenance planning?
. The PdM technology has the potential of greatly moving the plant’s ………. The entire plant must respect the importance of schedules and job priorities. and such clean surfaces to reveal the presence of new leaks. and project work to lessen the ……………………. for every forecasted work available. 11. Explain briefly the functions of maintenance planning. Why planning process is essential for efficient maintenance management? 2. Cleanliness helps reduce ……………. f) ………………………………………. Companies strive to do more preventive maintenance. to equipment. ………………….. allowing the crew supervisor to handle day’s work. 12. The principles used for planning and scheduling are for achieving the forecasted higher skill levels.. Improper lubrication leads to total ………. Crew supervisors forecast available work hours one week ahead by the highest skills available. …….. c. Just as in planning.e.. 3.. This requirement of corrective maintenance is ‘TLC’ i. ……………………………………………. The crew supervisor matches personnel skills and tasks] f. 6. Planners plan the jobs for lowest required skill levels. Schedule compliance joins wrench time to provide the measure of scheduling effectiveness. which are contributing to more than 50% of all breakdowns.e) Planners recognize the skill of the crafts. ………. work and to increase plant reliability.15 Terminal Questions 1. 14. Fill in the missing principle. 13. b.

7. no: e) Fix up the wages for each of the work based on the skill level 6. What is wrench time? How it is recognized as a maintenance work measure? 6. Work sampling for direct work time provides the primary measure of planning effectiveness 10. 8. workforce efficiency and of planning and scheduling effectiveness.4. Doing right jobs which are ready to go 4. 5. The extra labor power can be reallocated to added value activities. 9. Explain briefly how the use of six principles will greatly contribute to the overall success of scheduling 6. Productivity 9.16 Answers Self Assessment Questions 1. Why scheduling after proper planning is essential for effective maintenance and meeting the dead line and avoid delays? 10. “To increases the Maintenance Department’s ability to complete work orders quickly”. Lubrication.no:4)To arrest the leakages and keep up the lubrication system 3. and Cleanliness
. What are the maintenance planning principles? How they contribute to the success of planning? 8. Unnecessary job. 7. (sl. Incidence of reactive maintenance 11. Explain briefly the planning approaches in preventive and predictive maintenance processes. Productive time. (sl. Explain as to how the maintenance planning will help improve the effectiveness and efficiency of the organization 5. Tightness. Work plan 2. Explain how the specialization in areas of maintenance will help improve the productivity of the maintenance crew.

organizations have tried and tested different approaches for bringing changes that can result in improvements in both the function and the cost.9 Summary 7.2 Planner’s Function in Maintenance & Benefits 7. Using a state-of-the-art maintenance management.7 ACE Team Benchmarking Process 7.11 Answers 7.8 Overall Craft Effectiveness & its Measurement 7.OM0006-Unit-07-Universel Maintenance Practices
Unit-07-Universel Maintenance Practices Structure: 7.3 Organization & Processes 7. The new system will become a platform for continuous improvement and will generate long term benefits
.4 Benefits of using ‘UMS’ with Planner’s Functions 7.5 Universal Principles for higher Productive Maintenance 7.1 Introduction Automating the maintenance program is a complex task as it requires integrating of people.10 Terminal Questions 7.1 Introduction Objectives 7.6 Work Measurement for High-Productivity Maintenance Universal Maintenance Standards [UMS] Five Levels of Data in Ums 7. process and systems.

· Explain the benefits of UMS · Adopt the ACE system of Benchmarking 7.The analysis and application of work measurements to ensure improved productivity and cost reduction in maintenance should be the prime consideration by the management. cost reduction and its measurement 5. theory. materials and overhead. are the concepts. For achieving the above said prerequisites. Implementing new techniques of measurement. on-time delivery and ultimately. principles and theory of new measurement techniques. Engineering or Industrial Engineering managers spearhead their achievements of dramatic productivity improvements by adopting different methods of work measurements in managing and controlling their activities. higher quality. Achieving excellence in Maintenance Engineering and Management Objectives: After studying this unit you shall be able to: · Outline the functions to be performed by the maintenance planner. some of which are listed below: 1. Improving Wrench time of the Crew in Maintenance 6. Improving the Overall craft effectiveness [OCE] for productivity. Higher productivity maintenance means better customer service. a detail analysis and adopting certain state of art principles and improve maintenance productivity are all the focus areas for the above said disciplines.2 Planner’s Function In Maintenance & Benefits The planner’s role is varied in nature such as: maintain a backlog of ready-to-work jobs for each technician. satisfied customers. as the maintenance represents variable operating cost which includes physical plant value. close communication with supervisors. Benchmarking the best practices 3. systems and techniques of Universal Maintenance Standards [UMS] 2. field checks jobs when
. maintenance labour. Adopting ACE system for benchmarking and improvements 4. How the Maintenance. Use of the state of art principles. especially when sophisticated high tech machineries and equipments are used for production.

identifies special tools.needed. The planner also develops bench marks and maintains the data library. issue of stores taking too long. are validated.
. They can also establish a computerized maintenance management system. crew size. plans safety requirements. Hence the measurement provides information to determine the savings potential and also justify the maintenance work measurement program.3 Organization & Processes The tasks for a maintenance work measurement program fall into two categories namely 1) Organization and 2) Process a) Organization with planner in the forefront Planner maintains and allocates the work and knows all the ratios required for accomplishing the jobs and have good maintenance skills and experience and capabilities to work as the ultimate expert system. do the training. unrealized opportunity etc. The normal ratio of planners to technicians used is 20 to 30:1. crafts needed. the same can be raised to around 80% when a planning function is integrated with UMS times to work together. life cycle cost reductions d) on time completion of jobs e) continuous improvements f) improved service to customers. and make available to the crew a set of basic processes and craft operations for the process before establishing bench marks. b) Processes Processes involve data development and work order planning. In addition the resultant productivity improvement that accrues are the benefits to organization in a) cost reductions b) downtime reduction. While the maintenance departments without planners can achieve around 50-60% Productivity. based on a formal planning function and the Universal Maintenance Standards. Planners develop all the data. Importance of work measurement and the standard for the job should be established. Both the planners and the maintenance crew should examine to see how the UMS times could be applied. etc as well as the stores process to check the inventory value. verifies priority. plans work content. or too many stock-outs. materials. time reporting on the performance including delays.4 Benefits of Using ‘Ums’ with Planner’s Functions It is found that when a planner’s function is integrated with the UMS resultant impact is of improving the overall maintenance effectiveness. 7. requisitions non-stock or out-of-stock items. cost of the items. and time to do the work. 7.

7.1 Universal Maintenance Standards [UMS]
.6 Work Measurement for High-Productivity Maintenance 7. Hence the Universal Standards serve the special needs of maintenance work through the following principles: a) Scientific Principle Best productivity results when each worker has a definite job to do in a definite way within a definite time. Timely accomplishment is also universal phenomenon. but also helps growth in value added processes.5 Universal Principles for Higher Productive Maintenance There are several principles that. lead to the lasting results. d) Customer/Service Relationship The customer decides what is needed from an operational viewpoint. c) Activity Responsibility The responsibility for each activity of a work order is necessary to ensure that the work order continues to move toward resolution without delay.7. It is universal. Lord Kelvin saw this in his scientific investigation of the laws of physics.6. e) Crew Size The optimum crew size for a maintenance job is the smallest that can perform the work using a specific method and execute in a safe & efficient manner. They highlight problems or roadblocks for completion of the project. maintenance is no exception b) Measurement Before Control The measurement of an activity is basic to its control. Frederick Taylor’s principle applies to all work. which can be accurately planned. and maintenance decides how the service should be provided. This principle is also universal. The standard crew size is one and any other size is exceptions to the general rule. if followed. Together the customer and maintenance crew decide the priority (based on resources available) and urgency of each task compared to other existing current works. f) Timeliness Large maintenance jobs are divided into smaller work orders.

or one country. Applying the specific standards to the daily maintenance workload requires answers for: which task standard is required. how much rust is present on them etc. electrical. masonry. to what precision. A simple task such as removing and replacing a part may take more or less time depending on how tight the bolts are. utilities. The combination of many elements requiring different maintenance tasks and varieties of skills warrants developing and maintain a library of enormous number of standards. b) Evolution of Universal Maintenance Standards (UMS) In the early 1950’s. as these standards offered flexibility and could be applied not just in one location. is it realistic to measure. If it is a low volume work done by multi skilled crew. engineers adopted new methods for analyzing and assigning standards to maintenance work. pipe. weld. the motion pattern for two tasks may be same and also time to perform the work is almost the same. custodial. Hence breaking long jobs down into elements have resulted in a large number of elements. This range of time is same in 95 % of situations and hence standard average time is applied and practiced 2) Work content comparison. Even though parts are different. industry or service enterprise. then the time
. The range-of-time technique recognizes the variable nature of maintenance works. instrument. the result is that the crew does longer cycle work compared to other production workers. There are at least four to five hundred different jobs. government. education or healthcare.The principles adopted for above said requirements are based on the application of work measurement in maintenance. IT management etc. some unique characteristics are revealed. Techniques: The UMS system is based on three important techniques: 1) Range-of-time. or tasks. If the time to perform similar tasks is known. but everywhere where maintenance work is performed –manufacturing. labour. For example. in each of skills of fourteen types of jobs: mechanical. HVAC. Each element requires further study followed by application of stopwatch time or a predetermined time system analysis to determine the exact time required for each through the method selected. which in turn depends on: a) Nature of Maintenance works: In maintenance works. to what volume of work etc. service. sheet metal. machining. paint. time taken for threading a one-inch nut on to a bolt by hand operation takes almost same time like that of screwing in a light bulb into the holder. finance. automotive. availability of such standards. carpenter. called ‘Universal Maintenance Standards’ (UMS). commercial.

common to all crafts. move. which are pooled as weld craft operations data. The variables like weight of the part. whether the how clamping of part is done etc are recorded in the table for further use as standards.2 Five Levels of Data in Ums 1) Basic Motions The foundation of UMS data is the predetermined time system for basic motions. 3) Craft Operations Some operation times are unique to a certain craft. namely 1) basic motions. body motions. becomes the standardization process and hence these are universally adopted. Five levels of data in the UMS library. machine settings and arc striking time etc. position and release. By using spread sheets. a planner is able to establish planning times for a large number of jobs using relative sample data of the benchmark jobs and publicise the data along with the step-by-step process. Spread sheet fills the additional needs of finding quickly the
. distance moved. 2) basic operations. Each of these motions are recorded and these data becomes the established times for future reference and standardization. This system analyzes and classifies data into basic motions and establishes a relationship between the motions and the time required to perform them. grasp. electrical. 3) craft operations. 7.that can be applied to any other similar task with + or – 5%. 4) bench marks and 5) spread sheets. For instance. 5) Spread Sheets. carpentry. where work measures are dividing into basic motions such as reach. Two widely used predetermined time systems are ‘Methods-Time Measurement’ and ‘Operation Sequence Technique’. engineers can typically apply standards to all maintenance work with bench marks covering all the crafts and through the use of spread sheets they can substantially reduce the data library compared to the one with direct standard method. using the work content comparison technique is possible. Similar craft data for other skilled craft operations such as painting. welding operations are made up of manual handling. 2) Basic Operations Basic motions are grouped together to form basic operations. machining could be made available for the crew of maintenance 4) Bench Marks Using UMS. 3) Organizing the data UMS data is organized in a building block fashion.6. pipefitting.

Here the emphasis is placed on improving current repair methods. The allowances applied to these set times to get a single UMS time calculation for use by the crew. area travel time. bringing control systems.7 ACE Team Benchmarking Process “A Consensus of Experts” (ACE). the technique which was formulated and developed by the ‘The Maintenance Excellence Institute’ [TMEI]. have developed a bench marking process for the major work areas/types of maintenance operations. and in mechanical fields like Belt drives. supervisors and planners
. and lubrication and service. who have performed these jobs earlier and have requisite experience to improve upon them. reducers and gear boxes. outlines a new and highly recommended methodology for establishing ‘team-based maintenance performance standards’. 7. Spreadsheets are then provided for each work group having a time slots or range of times. a team of relatively small in number. 2) Objective of ACE Team Benchmarking Process Objective is to determine the reliable planning times for a number of selected “benchmark” jobs and to gain a consensus on the predetermined work content time. job site time and allowances for personal. which is called as ‘Reliable Planning-Time standards’. continuous improvement and the changing of times in performance and methods. 1) ACE System & UMS Using predetermined standard data.appropriate one for an application or finding the right bench mark for comparison. 3) ACE System: a Team-Based Approach ACE Team process is to obtain the most reliable. in motors. material handling equipment. reasonable estimate of maintenance “work content” time from a group of experienced crafts people. say within 95% confidence range. Spreadsheets include brief descriptions of the benchmark jobs and represent pure wrench time. This new Benchmarking Tool through ACE. These Benchmarked jobs are then arranged into different time categories on spreadsheets for various craft work areas. Ex: Benchmarking and firming up the task can be easily done in areas like lighting. All work order times released for the jobs and it consists of four components: job preparation time. The ACE System is used to develop maintenance performance standards. ACE Team Benchmarking Process parallels the UMS approach in that the range of time and the work content times for a representative number of benchmarked jobs are established. compressors. rest and minor unavoidable delays. the standards are established. clutches and brakes. in generators. which are then imposed on the maintenance force. which are reliable and a well-accepted planning times for the entire maintenance crew.

which will provide the management with a valuable input data for backlog determination. safety and quality b) Establish work content time for selected “benchmark jobs” for planners and others to use in developing reliable planning time. c) How OCE impacts the bottom line: Craft Labor Improving Overall Craft Effectiveness is getting maximum value from craft labor resources and higher craft productivity. preventive/predictive maintenance. Computerized maintenance management system (CMMS) could also be practiced. a) Improve current repair methods. and engineered standards such as Universal standards. scheduling. planners and other knowledgeable people to do two things. 7.and provides an excellent means to evaluate repair method. historical data. safety practices. Labour standards will be the baseline for determining craft productivity and improved methods. manpower planning. 6) The ACE System Supports Reliability Improvement: ACE Team process can contribute significantly to reliability. b) Investment for Planners: The planner’s activity with the team approach of ACE system will establish maintenance performance standards. 4) Recommendation of ACE System ACE Team overcomes many inherent difficulties associated with developing maintenance performance standards and hence recommended as the standard process for modern maintenance management.8 Overall Craft Effectiveness [OCE] & Its Measurement a) Craft Performance element of Overall Craft Effectiveness Determining the required standard hours of a technician require a trail run of the task under standard operating conditions. technicians. budgeting and costing. as its application promotes a commitment to quality repair procedures. Other methods used include reasonable estimates. effective storerooms and
. supervisors. 5) ACE Team Benchmarking Process: ACE System is a true team-based process that utilizes skilled crafts people. risks analysis on jobs that leads to improvements. Best practices such as effective maintenance planning/scheduling.

4. how efficient the hands-on craft work is done compared to an established planned time or performance standard. g) Craft Performance Another key element of OCE is the craft performance i. 6. Craft performance is directly related to individual craft skills and overall trades experience. 8. 9. productive work (wrench time). drawings. 2. 20 to 30 % can be expected from more effective maintenance planning & scheduling. This element includes quality of the actual work. Running from emergency to emergency in a reactive. Measuring and improving overall craft effectiveness (OCE) is one of the components of continuous improvements d) Effective Craft Utilization (CU): Craft Utilization or pure wrench time relates to measuring how effective the work is planned and craft resources scheduled so that these assets are doing value-added. Effective planning/ scheduling is the key to increase wrench time and craft utilization. 3. planned maintenance and more productive “wrench time”. where certain jobs possibly require a call back to the initial repair thus requiring another trip to fix it right the second
. shop clean up time Lack of effective planning and scheduling
Craft Utilization (or wrench time) is measured as the ratio of: CU %=100x [Total Productive hours or wrench time]/ [Total craft hours allotted x amount paid] f) Improve Wrench Time original Significant tangible benefits can be realized by increasing the wrench time. documentation etc.e. Waiting for the equipment to be shut down for work start Waiting for contractor support to arrive at job site Waiting on other crafts to finish their job Travelling to/from job site Make-ready. h) Craft Service Quality (CSQ) Another element affecting the overall Craft Effectiveness relates to the quality of the repair. e) Productive Wrench Time: Pure wrench time is just the actual output/work done and do not include the miscellaneous waste time caused due to any or many of the following: 1. fire fighting mode Waiting on parts and searching parts or part information Waiting for asset info. the personal motivation and effort of each craftsperson. repair instructions.continuous parts support will all contribute to proactive. 5. 7.

Profit-centred in-house maintenance in combination with the wise use of high quality contract maintenance services will be the key to the final evolution that occurs. Organization should not indiscriminately cut craft labour resources when increase OCE is warranted. OCE is increased people asset availability and capacity. It is gained value that can be calculated and estimated and then measured. b) Benchmarking the best practices. the overall Craft Effectiveness and provide value added maintenance services all the time with a profit oriented approach Self Assessment Questions 1. Measuring and improving Overall Craft Effectiveness and the value received from improving craft assets is an important part of total asset management. new techniques of measurement. Organizations should recognize maintenance as a core business requirement and should establish the necessary core competencies for survival. For improving maintenance productivity. c) Adopting ACE system for benchmarking and improvements d) ……………………………………………………………. In relation to OEE.time. implementation of certain state of art principles. Craft Service Quality will suffer due to hasty repairs. K) Maintenance is For ever Maintenance is a core requirement for profitable survival and total operations success. then Overall Craft Effectiveness Factor can be determined by multiplying each of these three elements: Overall Craft Utilization = [Craft utilization (%) x Craft performance (%) x Craft service quality (%)] i) Where Can We Apply OCE Gained Value Maintenance operations that continually fight fires and react to emergency repairs never have enough time to cover all the work (core requirements) that needs to be done. j) Think Profit-Centred Maintenance leaders and crafts people must develop the “profit” mindset to be competitive and stay in business.
. When reliable data is present for all elements. and a detail analysis of: a) Universal Maintenance Standards. patch jobs or inferior repair parts/materials. If the internal core competency for maintenance is not present it must be regained and ensure that they are profit-centred maintenance providers by understanding clearly the UMS.

9. 3. . The resultant productivity improvement that accrues because of integrating planner’s function with UMS will substantially benefit the organization in the following areas of operations/ functions: a. Life cycle cost reductions d. The Universal Standards serve the special needs of maintenance work through the following principles: a) ………………… b) Measurement before controls c) activity responsibility d) customer/service relationship e) Crew size f) Timeliness 6. based on a formal planning function and the. identifies special tools. Downtime reduction and its savings c.e) Improving the Wrench time of the Crew in Maintenance 2. Cost reduction and its total savings b. ……………………………….. a team of relatively small number of representatives. The planner’s role is varied in nature such as: maintain a backlog of ready-to-work jobs for each technician.
. 4.. Continuous improvement opportunities and gain in competitive advantage f.. plans crew size. Hence the measurement provides information to determine the savings potential and also justify the maintenance work measurement program. Improved services to customers g. materials. ACE Team Benchmarking Process parallels the UMS approach in that the …………………….. and time to do the work. 5. ………………. ……………. and e) spread sheets. 8. verifies priority. requisitions non-stock or out-of-stock items. Contributes in meeting other goals and objectives in the strategic plan. …………………………………………… e.. close communication with supervisors. ………………………………. who have performed these jobs and have the requisite experience to improve upon them. have developed a bench marking process for the major work areas/types of operation.. checks jobs when needed. Five levels of data in UMS are: a) basic motions b) Basic operations c) Craft operations d) ………………. The UMS system is based on three important techniques: a) Range of time b) …………………………… c) organizing the data 7. when once the ‘work content times’ for a representative number of ‘benchmark jobs’ are established..

Spreadsheets include brief descriptions of the benchmark jobs and represent ………………... ACE System is a true team-based process that utilizes skilled crafts people... preventive/ predictive maintenance....10. is getting maximum value from craft labor resources and higher craft productivity. 16.. 18... within the 95% confidence range... ... The new system will become a platform for continuous improvement and will generate long term benefits
.9 Summary By using a state-of-the-art maintenance management.. organizations have tried and tested different approaches for bringing changes that can result in improvements in both the function and the cost...... time from a group of experienced crafts people.. ACE Team process can contribute significantly to ……………… as its application promotes a commitment to quality repair procedures. 15.. Pure wrench time is just the ……………………….. 14. safety practices. Craft Utilization or pure wrench time relates to measuring how effective we are in planning and scheduling craft resources so that these assets are doing …………………... ACE Team process is to obtain the most reliable...............]/ [Total craft hours allotted x amount paid] 19.. .... and do not include the miscellaneous waste time caused due to any of the reasons. Overall Craft Utilization = [Craft utilization (%) x .. supervisors.. a) ……………………………………………………………………. b) Establish work content time for selected “benchmark jobs” 13. 17. risks analysis on jobs that leads to improvements. Craft Utilization (or wrench time) is measured as the ratio of: [ .... Best practices such as effective maintenance planning/scheduling...... reasonable estimate of maintenance ………………….. Spreadsheets are then set up with each work group having a time slots or ……………………. Improving ………………………. technicians........ planned maintenance and more productive ………………. planners and other knowledgeable people to do two things...... (%) x Craft service quality (%)] 7.. supervisors and planners and provides an excellent means to evaluate repair method.. 11........ effective storerooms and continuous parts support will all contribute to proactive.. 12.

The ACE System is used to develop maintenance performance standards. Improving Overall Craft Effectiveness is getting maximum value from craft labor resources and higher craft productivity. is a team of relatively small number of representatives.Higher productivity maintenance means better customer service. the concepts. measurements by using UMS and
. higher quality. Overall Craft Utilization = [Craft utilization (%) x Craft performance (%) x Craft service quality (%)] Maintenance is a core requirement for profitable survival and total operations success. life cycle cost reductions d) on time completion of jobs e) continuous improvements f) improved service to customers. who have performed these jobs earlier and have the requisite experience to improve upon them. organizations should clear understand of the Overall Craft Effectiveness. principles and theory of new measurement techniques that are used are: a)Universal Maintenance Standards. b) Benchmarking the best practices c) ACE system for benchmarking and improvements d) Overall craft effectiveness for improved productivity and cost reduction and its measurement e) Improving the Wrench time of the Crew f) Achieving excellence in Maintenance Engineering and Management The resultant productivity improvement and benefits that accrues because of integrating planner’s function with UMS are: a) cost reductions b) downtime reduction. or one country. Pure wrench time is just the actual output/work done Measuring and improving Overall Craft Effectiveness and the value received from improving our craft assets an important part of total asset management. industry or service enterprise. These Benchmarked jobs are then arranged into different time categories on spreadsheets for various craft work areas. which are reliable and a well-accepted planning times for the entire maintenance crew. Craft Utilization or pure wrench time relates to measuring how effective the craft resources so are doing value-added. develops a bench marking process for the major work areas / types of operation. For gaining the internal core competency in maintenance. The Universal Standards serve the special needs of maintenance work through the following principles: a) Scientific control b) Measurement before controls c) activity responsibility d) customer/service relationship e) Crew size f) Timeliness The Universal Maintenance Standards offered flexibility and could be applied not just in one location. satisfied customers. For achieving high productive maintenance. but everywhere where maintenance work is performed and is based on three important techniques: a) Range of time b) work content comparison c) organizing the data “A Consensus of Experts” (ACE). on-time delivery and ultimately. productive work (wrench time).

providing value added maintenance services on a most profitable manner are essential processes. 7.10 Terminal Questions 1. Why application and analysis of work measurements are important in maintenance management? 2. Which are all the concepts, techniques and principles used in measurement of work effectiveness and efficiency in maintenance? 3. Why planner’s role is vital to maintenance and how it improves the effectiveness? 4. Explain briefly the categories to which the tasks of work measurements can be grouped? 5. Explain the benefits that accrue to organization by integrating planner’s works with UMS? 6. Universal Standards serve the special needs of maintenance work through principlesWhich are these universal principles used for higher productive maintenance? 7. What are the three important techniques on which the UMS depends? 8. Explain briefly the five levels of UMS library and how each one is very important criteria for work measurement and analysis? 9. Explain the importance of using spread sheets and bench marks in work measurement to improve maintenance effectiveness? 10. “New Benchmarking Tool through ACE technique outlines a new and highly recommended methodology for establishing ‘team-based maintenance performance standards’, which is called as ‘Reliable Planning-Time standards” –explain how ACE will serve the organization’s needs in maintenance? 11. What is meant by Ace Benchmarking system and to what type of process it is recommended? 12. Explain overall performance effectiveness and how it helps in analyzing the performance of wrench times? 13. What is meant by effective craft utilization and productive wrench time & what are the factors constituting the craft utilization? 7.11 Answers

not outside parties. approval.2. providing mechanisms to ensure that documentation in the organization is uniquely identifiable reviewed and approved by the appropriate authority prior to release. This entails answering questions such as: · What types of QMS documents are required? · How should the QMS documents be logically structured? · How should the QMS documents be uniquely identified? · Who should review and approve documents? · How should changes to QMS documents be identified and controlled? · How should superseded (or obsolete) documents be handled?
. the primary users of an organization’s QMS documentation are its employees. Documentation strategy This is perhaps the most critical element of QMS documentation planning. and archived when obsolete (to prevent unintentional use). review. will provide you with a documentation set that is usable. and 3. and dissemination of QMS documentation. Documentation management and control mechanisms. Process for creating QMS documents. Brainstorming the documentation strategy entails obtaining answers to the following questions: · What approach should be adopted for documenting the QMS (top down or bottom-up)? · Up to what level of detail should processes be documented (breadth and depth of documentation)? · How can the QMS documentation be kept relatively stable and immune from minor changes in the organization or its processes? Documentation management and control Documentation management and control are a key element of an organization’s QMS. made available to users. After all. Document creation can proceed unhindered once the necessary guidelines are in place to support the creation. changed in a controlled manner. perhaps most importantly. not one written primarily to appease external quality auditors. rational approach to documenting your QMS will enable you to rapidly develop a QMS that works and has sufficient but not excessive detail. Agreeing upon such issues up front will facilitate the creation of the QMS documentation. A wellthought-out. and. kept current.

and other needed documentation.e. the process that results in a formalized set of product requirements may be identified as the product requirements definition sub process that is documented in a product requirements definition procedure.2 Documentation Strategy The top-down approach to implementing and documenting the QMS is highly recommended (as opposed to the bottom-up approach). how should the QMS documentation repository be published? · How should the published QMS documentation be organized to maximize ease of use for employees? Documentation process The third element of QMS documentation planning entails the establishment of a process for the creation. The procedures describing the sub processes and their interaction should be supported by additional QMS documentation. Similarly. approval. review. Within the product development process. hardcopy) repository or an electronic (i.· How should documents of external origin be controlled? · Should the QMS documentation be stored in a physical (i. and final release of QMS documents.. virtual) repository? · How employees should be provided access to controlled QMS documentation. What is the right level of detail to include in the documentation so that it enables correct and
. the product design sub process should be supported by QMS documentation such as a design document template.e. rework. For example. that is. a product design guidelines document. as appropriate. the process that results in a formal documented design for the product may be identified as the product design sub process that is documented in a product design procedure. the overall process that results in a delivered product the product development process may be documented in a product development procedure and/or in a product development process map. Another important issue that needs to be addressed regards level of detail. For example. Objectives: After going through this unit you will be able to: · Describe what is documentation strategy · Outline a documentation strategy for a unit or an enterprise · Construct a process map for documentation · Compose a QMS for a documentation process 8..

Therefore. and another procedure Y needs to refer to the same activity. QMS documents should be written so that they need minimum change. or other factors. and control of processes. Include only as much information as is necessary to ensure effective planning.consistent process execution. type of activities.” you need not revise your QMS documents if the functional responsibilities for testing the product still reside with this group. complexity of the process being documented. Often departments in organizations are renamed or merged into other departments. instead of saying that Mark Peterson produces the product requirements document. Some useful tips to accomplish this are:
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Always refer to roles (or functional areas) that are involved in the execution of a process. or conducting employee training to emphasize key aspects of a process. If an activity is described in a procedure X. state that the requirements document is produced by the requirements engineer. Other factors that have a bearing on extent of QMS documentation include size of the organization. review of existing QMS documentation to identify and correct deficiencies. but might result from unclear or ambiguous QMS documentation.” then refer to this department as the test department. it is far more convenient to revise one QMS document than to revise multiple documents. organizations should be careful in how they respond when process execution deviates from requirements. Include all information that is specifically required to be documented as per the applicable quality management system standard. To minimize the impact of such reorganizations. and competency level of employees executing the processes. Such an organizational change can have a huge impact on the QMS documents. as opposed to referring to individuals by name. For example. Creating more QMS documentation is not necessarily the right solution. if your organization has a product test department that is called “system test department. Below are some guidelines to follow to ensure QMS documentation has the right amount of detail: 1. state in procedure Y that detailed description regarding that activity can be found in procedure X. if any. for minor operational or organizational changes. refer to them by the “function performed. In the event of any change in the execution in that activity. and minimizes impact (on QMS documentation) of minor changes in the business processes and organizational structure? Any breakdown or inconsistency in process execution does not necessarily result from insufficient QMS documentation. Do not document details of an activity in more than one QMS document. instead of referring to departments by name. If this department subsequently is renamed the “independent verification and validation department.
. operation. 2. Sometimes.” For example. 3. is the preferred solution. inadequate employee training.

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When referring to another department’s QMS documents. A controlled document is one that is formally approved and is under formal version control. it is necessary to introduce the concepts of controlled documents and document controller. such as procedures. Depending on the size of an organization and/or its number of locations. and enforce an organization’s documentation management and control function. 4. monitor. Generally. For example. Documentation process of __________ planning entails the establishment of a process for the creation. the document controller function may be centralized or distributed.3 Documentation Management and Control 8. QMS documentation includes ______ of the organization. 8. Implementation-level QMS documents typically are more prone to changes in content. refer only to its highlevel QMS documents. type of activities. but are not limited to: 1. _____________ should be written so that they need minimum change.1 Role of the Document Controller Before discussing different elements of document management and control. in case of companies with more than one location (or very large companies in a single location).3. 5.g. department Y’s procedure refers to department X’s work instructions. Certainly it is quite inconvenient for department Y to revise its procedure when department X revises its work instructions such that the reference from department Y’s procedure becomes inaccurate. it is best to control documents that affect an entire company (e.
Self Assessment Questions 1. QMS documentation that pertains to a specific location (or a specific function) may be controlled locally. Documentation __________ and control are a key element of an organization’s QMS. company quality manual and operating procedures) in a centralized location. Document controllers are people who coordinate. Verifying that documents submitted for storage and publishing are:
. A document controller’s responsibilities generally include. 2. and scope than are high-level documents. title. However.. 3. Avoid references to another department’s work instructions or similar implementation-level documents. The ________________ to implementing and documenting the QMS is highly recommended.

8. Notifying affected personnel in the event of a change to a previously approved document (or release of a new document) 9. 6. 4. Ensuring that all controlled documents are stored in a secure location. Duly approved c. Verifying that the documents are correctly versioned. Controlling documents of external origin.3. a document number may be generated automatically.a. Accompanied by review records (when required) 2. Verifying that the documents are correctly numbered. such as the document author and management personnel from the affected area. 3. 10. When document numbers are issued manually for new documents. This is necessary because the document author may make document changes in addition to those that were authorized. the document controller should verify that the document version accurately reflects the magnitude of change in the latest version. Verifying that changes made to previously approved documents were properly authorized (that is. 8.2 Types of QMS Documents Quality Manual
. they adhere to standardized templates when applicable) b. 12. Verifying that all changes made to previously approved documents are clearly identified. Maintaining a master list of controlled documents. for revised documents. Authorizing internal documents for external release after verifying that approvals for the release have been obtained from relevant management personnel. this task generally is performed by the document controller. In case of changes to previously approved documents. when errors or discrepancies are observed. This includes withdrawing copies of obsolete controlled documents. In the correct format (that is. This includes clearly identifying documents of external origin and storing them in a secure location. Notifying appropriate personnel. Alternatively. an approved document change request should be available) 7. 11. Correctly storing and publishing (or distributing) controlled documents. 5.

Senior management should realize that it is responsible for the manual’s content. employees typically relate more closely to organizational processes than to the requirements in a quality management system standard. in the case of smaller companies. prefer to structure their manual to mimic the structure of the applicable quality management system standard. and not in the context of a quality management system standard.
. it may be appropriate to include the procedures in the quality manual itself. This approach entails describing the high-level product development process map of the organization. which must be referenced. answer why the organization is implementing a QMS) and describe how the organization ensures quality in its daily operations. It therefore should reflect the organization’s commitment to quality (in other words. When appropriate. such as ISO 9001:2000. Such a quality manual includes separate sections (or subsections) for each of the requirements sections (or subsections) in the quality management system standard. In case of medium and large product development companies. Such quality manuals follow a top-down approach to describing the organization’s QMS. QMS documentation in explaining adherence to each quality management system standard requirement. Typically. This includes describing the purpose and scope of each process. organizations structure their Quality Manual in one of two ways: 1) Standard-based quality manual Most organizations that are implementing a QMS in accordance with the requirements in a particular quality management system standard. it is preferable to exclude details regarding the organization’s processes from the quality manual. customers (and potential customers). as needed. An organization’s quality manual is an invaluable document for its employees. and consequently it gains wider acceptance for daily operations. from the quality manual. The QMS is explained in the context of the organizational business processes. However. along with a reference to related QMS documentation. Each section (or subsection) in the quality manual describes how requirements in the corresponding section (or subsection) in the quality management system standard are adhered to in the organization. and other parties (such as third-party auditors). followed by separate sections briefly describing each key process in the QMS. 2) Process-based quality manual This structure is being used increasingly in organizations that have successfully transitioned to taking a process-oriented view of their QMS. employees invariably prefer such a quality manual. The quality manual must reflect the QMS accurately and be kept current at all times.A quality manual is the highest-level QMS document and is intended primarily to provide an overview of an organization’s QMS. A significant advantage of this structure is that it is not alien to employees. Therefore. Such details should be embedded in the appropriate QMS documents. This can be demonstrated by senior management approval on the quality manual. the quality manual references relevant.

Procedure A procedure is a documented high-level description of a process. and they constitute the first level of documentation below procedures. they should be documented and jointly reviewed by practitioners involved in executing the tasks documented. This helps ensure that the procedure accurately reflects the process and the interaction between various departments. and Where the activities are performed. Work instructions typically are intradepartmental and are intended primarily for use by process practitioners. They also serve as a valuable starting point for training process practitioners. Procedures are usually interdepartmental. because organizational processes typically span multiple departments. Procedures constitute the first level of documentation below the quality manual. When each activity in a process is performed. If a longer procedure is needed. Who performs the activities (roles and responsibilities). They describe: What activities comprise a process. practitioners typically need additional process documents. As a general rule of thumb. The decision to document a process in a procedure is made by the respective process owner in consultation with the quality assurance department. When process practitioners do not have the requisite training or are otherwise unskilled for creating effective process
. a procedure should not be longer than three pages. Work instruction A work instruction is a documented low-level description of a process. and experienced personnel for providing information on the execution of specific tasks. to execute their tasks. The practitioners have firsthand experience performing the tasks and therefore typically are the most knowledgeable. They provide a step-by-step description of tasks to be executed in order to accomplish each activity in the process. Procedures are useful for communicating process information at all levels of management between departments. it is a good candidate for splitting into separate procedures. Procedures are not intended to provide the how to implementation details regarding a process. Work instructions describe how activities in a process are executed. They serve as critical reference documents for anyone interested in knowing what a process entails. Due to the intradepartmental nature of work instructions. they should undergo cross-functional review by all departments involved in the process (or areas affected by the process) being documented. Due to the interdepartmental nature of procedures. called work instructions. Because a procedure is intended to contain relatively high-level information regarding a process. competent.

g.g. is there need to elaborate and provide further explanation on a process documented in a procedure by creating a work instruction (e. work instructions can help ensure consistency and minimize errors. to minimize variation..documentation. the greater the likelihood of inconsistency in process execution. this task may be performed by another appropriate person. Not every procedure needs to be supported by underlying work instructions. The need to document a procedure or work instruction may be determined by using criteria such as: Complexity Is the process or the activities in it sufficiently complex that that it needs to be supported by a documented procedure or work instruction? Or. In many cases.. such as the PMC representative for the department. in order to secure buy-in of the practitioners and to ensure that the documentation accurately reflects practice. the sequence of tasks to be performed during engine assembly for a passenger vehicle)? Need for consistency Are there expectations regarding a high degree of discipline and consistency in executing a set of tasks (e. the core description of tasks in a work instruction should be limited to about four or five pages in length. As a general rule of thumb. In such a case.) Size of organization Is the process executed by several personnel and/or in multiple locations? The greater the number of personnel involved in a process or the greater the number of locations at which a process is executed. the sequence of inspections to be performed before final approval for release of electronic wire assemblies)? Competence of personnel Is the competency level of the personnel executing the process such that it needs to be augmented with appropriate documentation to ensure the process is correctly executed? (For example. the work instructions should be documented with direct input and active involvement of the process practitioners. The decision to create a work instruction is made by the line manager or process owner who is responsible for the tasks. when new personnel or personnel with varying levels of competence are executing a process.
. Work instructions should be created on an as-needed basis when a need exists to provide detailed step-by-step guidance for process execution. processes that are relatively straightforward and without inherent complexity (or sophistication) can be described adequately in a well-documented procedure such that competent personnel can faithfully execute them without compromising quality of process output. and to ensure consistency in process execution.

Templates and forms A template is a skeleton for a document intended to be populated with specific information from use. The procedure author would start with the procedure template and populate it with information for the process being documented. A form is used to record information.3 Document Numbering In order to uniquely identify and control each QMS document. due to their very nature. and should be enforced by the personnel in charge of (or tool used for) issuing the document numbers. 8. such as procedures or work instructions. Table 1
. documenting an agreed way of executing a process can help. They help in ensuring consistency of format and content within a particular type of document. while the decision to create a template or form for departmental use may be made by the respective line manager. The decision to create a template or form for use across departments should be made by the respective process owner in consultation with the quality assurance department (for reasons described earlier). but retained for archival purposes). evolve. 8. a unique document number and version should be assigned to each document. It is recommended that forms and templates have brief instructions embedded in them to guide the user regarding the expected content in each section of the document. either for review or for use (after approval).4 Document Versioning Documents. For example. one must not only know what document to use. An example of a document numbering convention is shown in Table 1. Therefore. Any change or set of changes made to a document since its last release necessitates that the new revision level of the document be formally identified. it is strongly recommended that a procedure template first be established.3. Templates serve as guides for communicating the expected structure and content of a document. directly in the fields provided.Past problems Have there been instances in the past where inconsistencies in employees have been observed in process execution? In such cases. The organization should devise a document numbering convention that meets its needs. This is because the information contained in the new revision of the document is to some extent different from that contained in the previous revision. but also what revision level of that document to use. for documenting procedures. a document typically will undergo revisions until it is withdrawn from use (or considered obsolete. The numbering convention should be published in a QMS document. Once released.3.

Example of a Document Numbering Convention Document number format: AAA-BB-CCCC-DDDD where, AAA: Three-character identifier for department that is the document originator For example, “ENG” may denote engineering, “MKT” may denote marketing, “EXT” may denote the document is of external origin, and so on. BB: Two character identifier for document type. For example, “PR” may denote procedure, “TP” may denote template, “CH” may denote checklist, and so on. CCCC: Four-character alphanumeric identifier for project, product, or task. DDDD: Four-digit sequential number between 0001 and 9999. This sequential number uniquely identifies a specific document (irrespective of its version). 8.3.5 Document Content Following are some guidelines regarding document content (for examples, refer to sample QMS documents in the Appendices): 1. All QMS documents and records should have the same “look and feel.” Consistency in templates and forms can be ensured by following some general guidelines, such as:
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The same header and footer on all templates and forms, with information such as:

a) Document title b) Document number c) Document version d) A statement to indicate the company proprietary nature of the document
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Each QMS document, when appropriate, should use the same title page, containing the following:

– Standard information, (e.g., organization’s name and logo). The title page also can include a unique logo to indicate that it is a QMS document. This enables quick identification of QMS documents. – Customizable information, (e.g., document title) 2. Each QMS document or record should contain content as per the guidance contained in the associated form or template. Each QMS document must identify its purpose and

scope clearly. Correctness of the document content should be reviewed and enforced during document review meetings. 3. Deletions from the template and forms should not be allowed. If a particular section is not required, it should be marked “not applicable.” 4. Insertion of additional sections in a document created by using a standard form or template should be allowed when necessary; however, certain rules should be established to handle addition of new sections. Self Assessment Questions State whether following statement True or False. 6. All QMS documents and records should have the same “look and feel”. 7. A work instruction is a non-documented low-level description of a process. 8. A procedure is a documented high-level description of a process. 9. A quality manual is the highest-level QMS document. 10. A template is not a skeleton for a document intended to be populated with specific information from use. 8.4 QMS Documentation Process Now that all the necessary elements of a documentation management system have been described, you are ready to begin creating QMS documents. What documentation process should be followed to create, review, and approve QMS documents? This section describes a high-level documentation process that ties together some of the key elements of document management and control. Step 1: Identify suitable document author The first step is to identify a document author who possesses appropriate subject matter expertise. Typically, a management person from the function tasked to create the document selects a suitable document author. Step 2: Create draft version of the document The document author creates a draft version of the document by using the applicable template (if one is available). Step 3: Review the draft document

Once a draft version of the document has been prepared, it is circulated for review to appropriate reviewers (or functions) that are considered stakeholders in a document. The review may be in the form of an informal and/or formal review. Step 4: Rework the document as per reviewer feedback After receiving the feedback from the reviewers, the author reworks the document in accordance with comments provided by the document reviewers. Step 5: Approve and publish the document Once the document rework is complete, and it has been determined that a rearview is not required, the document is circulated for approval to the identified approvers. Once all the required approvals have been obtained, the author submits the master copy of the document along with the review record to the document controller. The document controller stores the document in the controlled repository and makes copies available for use. 8.5 Summary Documentation strategy is perhaps the most critical element of QMS documentation planning. Documentation management and control are a key element of an organization’s QMS, providing mechanisms to ensure that documentation in the organization is uniquely identifiable reviewed and approved by the appropriate authority prior to release. A template is a skeleton for a document intended to be populated with specific information from use. 8.6 Terminal Questions 1. Explain briefly different steps in documentation. 2. Define some guidelines in Documentation Strategy. 3. Explain types of QMS documents. 4. Summarize Document Content. 5. Explain QMS Documentation Process. 8.7 Answers Self Assessment Questions 1. Management 2. QMS documentation

9.12 Measurement of Maintenance Performance 9.13 Asset Life Cycle Management 9.14 Equipment Replacement Plans 9.15 Depreciation & Capital Expenditure based on Life Cycle 9.16 Summary 9.17 Terminal Questions 9.18 Answers to SAQ & Terminal Questions 9.1 Introduction The main function of the maintenance department is to monitor and control the condition of machineries and equipments and improve their functional reliability. The reliability theories on equipment performances have shown that there is a definite pattern of performance in their lifespan. This pattern manifests itself when different machineries are subjected to rigorous operations during the life span. The typical characteristics of the lifespan show a particular behaviour pattern of a bathtub and hence it is called as ‘bathtub curve’, which is discussed later. Objectives: After going through this unit you will be able to: · Describe what are failures in maintenance · Analyze failures through Weibull distribution curve · Discuss Reliability Performance · Construct a measure for performance 9.2 Functional Reliability of Facilities One of the most important objectives of Maintenance management is to improve functional reliability of the production facilities. The functional reliability refers to the consistency of the degree of performance of the machine, equipment or service operation. When it is said that a machine is having 97% reliability means that 97% of the machine time is utilized in performing the standard production for which it is meant for, and the remaining 3% of non performing may be

due to breakdowns or sub-standard performance. Therefore it is the duty of the plant maintenance crew to strive to maintain and increase the functional reliability of the production facilities. The objective of FMEA ( ) and reliability analysis of the plant and equipment is to ensure to excellence in performance of critical assets and achieve the business goals. The application of standard procedures and structured approach to analyse and practice effective method/s required to maintain all the operating plant assets. This process enables the maintenance managers to plan, review and optimise the maintenance operations that have direct impact on plant availability, thereby improving the overall plant performance and minimizing catastrophic failures. The functional reliability of facilities to be maintained or improved upon by the maintenance management requires the use of certain concepts, reliability methodologies, analysis, tools and techniques and measures. Some of these are listed: a) Determinate the appropriate level of maintenance services required. b) Identify specific actions based on equipment failures analysis & risk assessment. c) Prevention and reduction of potential failures by properly identifying defects and implementing corrective actions prior to failure d) To deploy sufficient staff to provide adequate repair and maintenance facilities. e) To provide for the stand-by equipment for key operations and also reasonable slacks in the production system to create some parallel path in a critical situation f) To adopt preventive Maintenance system to replace critical parts, before they fail. g) Each of the above involves costs. The cost involved should be justified on the basis of cost-benefit analysis. The cost of attaining reliability must be lower than the cost advantage available out of the production stoppages, idle machine and labour time, scrap, poor quality, loss of goodwill to keep delivery promises etc. h) Maintenance extends the useful life of assets by reducing wear and tear. i) Maintenance keeps up operational readiness of equipments for emergencies. j) Maintenance contributes a great deal to safety of manpower using the facilities. k) It prevents wastage of spares, tools and materials.

or sheer quality deficiency in their manufacture. it is important to know the nature and occurrence of failures over a period of time for the equipment in use. called the ‘Weibull distribution graph’ (after Weibull developed it). This is the useful period of the machine. a) Infant Mortality phase: Newly installed equipment shows high rate incidence of early failures during initial phase of its life. poor installation. This type of breakdowns may be due physical characteristics of the
. b) Useful Performance phase: Next phase is the useful period of performance with a better reliability. The failure is random and unpredictable. 9. The high rate of failure at infant mortality stage is primarily due to the presence of weak or substandard components or design inadequacies. c) Ageing Phase: Here the rate of failure increases until the equipment succumbs and is characterized by the rapid wear and tear of more and more components until major breakdown happens. It is also commonly called as ‘Bath Tub Curve’. because of its shape. there are three phases in the equipment performance namely a) Infant mortality phase b) Useful performance phase c) Ageing phase.3 Weibull Distribution Curve [Failure & Its Analysis] For better maintenance planning and control. and or not adjusted the operating conditions adequately. This behaviour pattern reflects ‘hyper-exponential distribution’. Most equipment that survives infancy stage will continue to perform better with very few failures. fatigue due to flaws in the molecular structure of the metals. During this period. Once this phase is over.l) More automation calls for sophisticated Maintenance. is shown below.
As per the graph. which is called the infant mortality. The graph of the failure pattern. the failure rate dips as the components adjust to the system until it reaches a relatively low constant level. the weak components from the infant mortality period have either been repaired or replaced. is primarily due to abrupt changes in stress distribution in the components.

· A simple machine having few moving parts may have breakdowns happenings after a large number of maintenance free run time hours. the failure fall into a negative exponential distribution. or how the machine is used. the breakdown time distribution of a complex machine will reflect a greater variability than that of a simple machine even if they have the same average maintenance free run time. This ultimate may occur at ‘mean’ or ‘average’ time. 9. Depending upon the complexity of the machine and severe aging processes because of extreme wear and tear results in an ultimate failure.4 Life of Equipment a) Bathtub Curve and MTBF · Weibull distribution or Bath Tub Curve. · Figure below represents the degree of variability in free run time. Distribution shows the frequency of maintenance free running time with respect to total operating hours. In other words. These causes being external to the equipment and the probability of failing is relatively constant.
. can be assessed. This means that each part in a particular machine will have different failure distribution. Mean Time between Failure (MTBF) can be computed. is a combination of three distributions: Hyper exponential.e. Negative exponential and Normal exponential. anticipated life etc. the failure of any one part may result in the complete machine breakdown. but in a complex machine. · When the failures are recurrent.materials used. · From these. A= [Tn] / [Tn+Td] b) Breakdown time distribution: · It is essential to know how the breakdown time is distributed in order to establish the cost implications in maintenance. shown above. by which the system reliability. This ageing failure graph shows a bell-shaped normal distribution pattern. availability. · The availability (A) = [Cumulative time of operation in the normal working condition(Tn)] / the cumulative down time (Td)] i. its statistics will help as a diagnostic tool in identifying the exponential nature of the availability and the reliability of equipment. and may be earlier or later.

It can be observed that the Curve A shows lower degree of variability. Curve B of the complex machine.6. the frequency distribution. The variability by Curve C is typical of complicated equipment that needs fine adjustments before it starts giving trouble free service. 0.7. we mean the probability that any system gives a trouble free service. then the total product reliability is multiple of all these systems i. For example: if the total system has four sub systems having the reliability factors of 0. curve B exhibits moderate variability while Curve C indicates greater degree of variability from average breakdown time Ta. but the distribution shows wider variability.9. the resultant graph is shown below. · When the above reliability factors are plotted in a diagram showing the percentage of breakdowns that exceed a given runtime on the ‘y’ – axis. Hence the reliability of the total system depends on the product reliability factors of each of the sub systems. Curve C has the same average maintenance free runtime as the other two.
.While curve A depicts the behaviour of a simple machine. and ‘runtimes free of breakdowns’ on the ‘x’ – axis. 0.and 0. · By reliability. converting the information into the breakdown time distributions versus the percentage of breakdowns that exceeds a given run time.8. Here the data can be recast in the diagram. c) Reliability and Variability of the Equipments · Equipment can be considered as a total system and the failure of any one of the sub system can cause failure of the entire system.4. before establishing reliability. 0.e.

As in other types of probabilities.5 Critical Analysis Critical analysis of maintenance problems is essential to know as to how serious is the problem for taking quick actions. the nature of the fault and availability of repair staff etc. Fundamental differences between the strategies discussed earlier and the proactive maintenance discussed now are: 1. Repair Maintenance 2.9. here too is that the small percentage of around 15-20% defects in equipment. Focus is not only concentrated on availability but also the reliability
. This activity may take a few minutes. In other words. or even a few days as the work involved depends on the size and complexity of the equipment. electrical or other fault quickly and to correct them. namely: 1. It is the job of the maintenance crew to identify and quickly eliminate or simplify or improve upon these defects. the repair maintenance crew endeavours to locate mechanical. the function presupposes the previous breakdowns and actions of disassembling the equipment. Preventive Maintenance When a sudden breakdown occurs in a machine. it is a corrective maintenance to restore the machine/parts to acceptable condition again. to locate the faulty/broken part. 9. to replace it. to reassemble the equipment and then check and restore to its functional capacity. may contribute to 80 to 85% of the total breakdown time. In this type of repair maintenance.6 Maintenance Performance Ratios Some of the ratios used in measuring the effectiveness of Maintenance functions are: a) Waste Index = [Waste Quantity] / [Output Quantity] b) Productivity of Maintenance = [Product output] / [Maintenance Cost] c) Maintenance Cost index = 100 x [Maintenance cost] / [Capital Cost] d) Breakdown maintenance index = [Break down hours] / [Man hours available] e) Downtime index = 100 x [Downtime hours] / [Production hours] 9.7 Maintenance Systems The ad hoc unplanned emergency maintenance is not recommended. but the two types of planned maintenance could be carried out.

2. the overall reliability performance of the total process is less and is dictated by the complex machine with lesser reliability. There is a push towards zero downtime or zero in-service breakdowns. Root Cause Failure Analysis (RCFA). 9. T = Time performance. 3.8 Reliability and Availability Concepts Reliability and availability have become key issues. quality and speed) · Mean production loss (MPL) Thus the reliability index is expressed in terms of the running continuously without production losses. and manufacture the quality product at the speed required. Q = Quality performance. There are many ways to measure reliability. · Mean Time between Failure (MTBF) · Measure of mean time between production Loss (MTBPL) (Production losses include loss due to time. Manufacturing reliability can be defined as a manufacturing system’s capability to operate to its expected operations. fix the problem as fast as possible. Say in a paper processing. This index is the volume of quality products you measure in the production line divided by the theoretical volume of quality product you could achieve from the same line. and others. For example. a tissue processing machine may give a good reliability of +98%. but when failures occur. 9. then lower is the reliability. a CNC machine can be very good at 90%. the formula used to measure manufacturing reliability (MR) is: MR = [% T] x [% Q] x [% S] [Where. S = Speed performance] Manufacturing reliability model consists of a) process reliability b) equipment reliability and c) reliability maintainability.9 How Good Is ‘Reliability Performance’? In industrial processes. Using the above definition. where as a less complex automatic lathe may be rated best at + 98%. more complex the equipment/ the raw material/ high tech processing. Use of improved maintenance tools such as Reliability Centred Maintenance (RCM).
. but the liquid packaging machine may be best at +75% reliability.

· While RCM is driven by preventive maintenance strategies. the team finds as many causes for the fault as possible and classify them into non contributing and contributing. Answering to seven questions on all the potential modes of failure will uncover the predictive maintenance strategy requires to mitigate the consequences of the failure. RCM provides a flow diagram that tells what type of maintenance to be used.a) Root cause failure analysis: · The root cause failure analysis (RCFA) method brings a knowledgeable team together to investigate certain failures using evidence left behind from the fault. When implemented together they complement each other and provide the greatest overall benefit to the facility.10 Maintenance Economics Maintenance refers to an organisation’s policy in respect of the maintenance function of a set of equipments. production. the team checks for the logical flows and determine what changes are to be made to prevent causes from reoccurring. b) Reliability centred Maintenance · The purpose of reliability centred maintenance (RCM) is to determine the maintenance requirements of any physical assets in its operating contexts. Through a fault tree analysis.11 Preventive Vs Breakdown Maintenance Certain generalizations on type of maintenance can be made to improve the reliability: a) First. hygiene. customer service. what are its cost implications? 9. The decision of maintenance policy is more of an economic decision rather than a technical one. c) Failure Modes Effects Analysis & Total Productivity Maintenance · Total productive maintenance (TPM) and failure modes and effects analysis (FMEA) are other maintenance tools used for improving the reliability through proactive maintenance. quality. 9. In this situation. preventive maintenance is highly beneficial to machines whose breakdown time distributions are having low variability. engineering. Through brainstorming sessions. planning and organisational leadership.
. a standard preventive maintenance period can be set in such a way that the total downtime is reduced. RCFA is driven by maintenance prevention strategies. It has relevance to high volume production and can improve a company’s maintenance system and help improve the overall productivity of the processes. This practice has impact on many aspects of business. As maintenance is an economic decision. Non contributing causes are removed from the list and contributing factors are taken for analysis.

reduces costs and eliminate waste. Effect on production losses if plant shutdown can be avoided 3. 2. Analysis of data of the existing conditions with respect to down time production loss. Companies should recognize this fact that maintenance of its assets is to be encouraged as the process will provide advantages in enhancing quality initiative. Some metrics that may help in evaluation are: a) Maintenance man hours as percentage of total man hours b) Shutdown. existing maintenance facilities. or more than the time for repair.b) Second. nature of repair breakdowns. such as 1. the relation of preventive maintenance time to repair time is important. Hence maintenance and management of assets is the core to any business. increases capacity.12 Measurement of Maintenance Performance Organizations seeking excellence in their maintenance practices should constantly endeavour to measure and improve upon the performance criteria’s of maintenance. Additional stoppage time because the maintenance crew cannot start repairing immediately after the breakdown has occurred. etc are required to be done and evaluated. d) We need to take into account other effects of unscheduled down-time. 3) direct labour value
. the percentage of machine running time continues to increase with the increase of standard preventive maintenance period. when the repair time is equal to maintenance time. maintenance cost breakdown. c) In general. 9. There is little gain in the preventive maintenance. overhauls and renovations c) Production asset and loss d) Continuous reliability improvements e) Maintenance cost as a ratio of percentage of 1) gross asset value 2) sales value. if the maintenance time is less than the repair time and If the preventive maintenance is equal to. it is better to perform corrective or breakdown maintenance. Effects of scheduling preventive maintenance for non-productive days with no loss of production.

as evolved by some companies for better results consists of three phases: a) Asset Acquisition Phase: here asset may be new or replaced or change of major components changed before operating activities in this asset is firmed up. Asset life cycle management system. Factors that are considered while taking decision to replace machine and equipment can be classified as a) Technical factors b) Cost factors. then the asset is disposed off as it has reached the end of its lifecycle. c) Disposal Phase: when the asset is no longer capable of delivering the required operational performance or cannot be maintained cost effectively to achieve the required level of dependability.14 Equipment Replacement Plans The systematic equipment development program includes: 1) emergence of equipment replacement 2) classification of equipment replacement 3) assignment of responsibility for equipment replacement 4) selection of the equipment 5) follow up.13 Asset Life Cycle Management In high tech production.f) Safety and regulatory compliance 9. companies are required to produce more products of higher quality from fewer resources and hence maintaining higher reliability of assets has been a challenging task for the management. 9. Asset dependability and its reliability are to be established. b) Maintenance phase: operating environment for each asset is defined and performance goals at the lowest cost are firmed up. a) Technical factors that dictates replacement 1) Wear and tear of equipment 2) Obsolescence caused by new invention
.

will pay not only for equipment but also for any unamortized value for next few years.3) Unsuitability of equipment due to size of the work. 2) By Using Barnes Formula: this formula is used for equipment. accuracy. material losses etc. While the annual operating costs include wages to operator. Some important methods or replacement of old and unused machineries are 1) minimum annual cost method 2) by using Barnes formula 3) MAPI (Machinery and allied institute) method. 1) Minimum annual cost method: here the decision to replace the machine (unwanted or life is completed) is based on the operating and capital costs. old or new. X = (No. The main ingredients of the annual cost are depreciation and interest charges. power consumption. Hence the time for replacement depends on the condition and characteristics of the equipment. Here the replacement is not advocated unless savings due to the use of new equipment. of years the equipment will pay for itself) = [A+B] / [(E-F) DG + H – C]
. speed of operations. having a short life. repair and maintenance costs. consumes high power etc 4) Automation requirement for processes 5) To eliminate slack time through line balancing 6) Reduced safety 7) Reliability of performance b) Cost Factors: 1) High repair cost 2) Lesser place requirement 3) Probable economic life of the new machine 4) Consumption of less power 5) Reduction in labour cost because high productive machines purchased 6) Flexibility requirement not in the existing equipment Methods used for replacement after analysis: The replacement analysis becomes more complex due to many technical factors and qualitative considerations. rate of output.

It emphasizes on immediate return. and then sold for Rs. D = number of units product per day by new equipment. Additionally. · Depreciation should be calculated in a way which most closely reflecting the manner in which the asset is being used up. the value of the asset in the balance sheet should be reduced by each year’s charge. Depreciation tries to apply the accruals by matching that Rs. G = estimated working days per year for new equipment and H = savings or losses per year in fixed charges other than interest] 3) MAPI method: here the analysis is divided into 35 heads & three main groups. C = interest charge of new equipment. The two most commonly used methods are straight line method and reducing balance method.15 Depreciation & Capital Expenditure based on Life Cycle · This requirement falls into the following groups: a) Calculation of depreciation b) Calculation of profit/loss on disposal c) Accounting for depreciation and disposals Calculation of Depreciation · Capital expenditure is that spent on purchase or improves on fixed assets. if an asset is purchased for Rs.10000. whilst revenue expenditure is that spent on day to day business expenses. 9. For example.1000. Straight Line method 1) A fixed percentage on cost each year. but shown in the Balance Sheet · Depreciation is an attempt to spread the cost of an asset over its useful economic life. Capital expenditure is not recorded in the Profit and Loss account.9000. E = labour cost per unit in old equipment. · An annual depreciation charge is shown as an expense in the Profit and Loss account. it has the business cost of Rs. 2) The same monetary amount each year
. MAPI method concentrates on the comparison of the rate of return of the proposed new project and similar returns when the proposed project is not implemented within next year. kept in use for 8 years.9000 with the income that asset has generated. F = estimated labour cost per unit with new equipment. B = depreciated value of the old equipment.[where A = cost of new equipment.

6000 b) Year 2 (Rs.6000) x 20% =Rs.
. It is expected that this machine will be used for 10 years.30000. Calculate the depreciation to be charged for each of the first 3 years of the machine’s life. 2850) · So. at the end of which it will be sold for Rs. (Rs. On disposal.30000 – Rs.30000 x 20%= Rs. This over or under provision of depreciation is shown in the Profit and Loss a/c as a profit or loss on the disposal of fixed assets.1500. the actual disposal proceeds will show the true net cost of the asset. ] Reducing balance method (the charge for depreciation reduces each year) a) Year 1 Rs. i. · [Note that the policy could have been expressed as “straight line at %” or “Depreciation at % pa on cost” – here the percentage is calculated as = Rs.1500) / 10 = Rs.e. i.30000 – Rs.6000 – Rs.2850.30000 x 100.30000 – Rs.e.4800) x 20% =Rs. the annual charge for every year of the machine’s life is Rs.3840 and so on.Reducing Balance method 1) A fixed percentage on net book value each year 2) A reducing monetary amount each year Example: 1 a) Straight line method A machine is purchased for Rs.2850 / Rs.4800 c) Year 3 (Rs. using: (i) The straight line method (ii) The reducing balance method at 20% pa Solution · Under the straight line method. [Note that the expected residual value is ignored & it will have been incorporated into the choice of 20% as an appropriate rate] b) Calculation of Profit/Loss The depreciation charged each year is based on estimates of useful life and residual value. This may reveal that two much or too little depreciation has been provided over the asset’s life. the net cost is simply divided by the expected life.

2520] c) Accounting for depreciation and disposals · In the above example. and is depreciated using the reducing balance method at 20% pa.Example: 2 An asset is purchased on 1 January 2006 for Rs. Solution · Sales proceeds must be compared to the net book value on the date of disposal.03-2009 (20%) =5120 · Net book value at 31. 23000 – 20480 (book value) = Rs.03-2008 (20%)= 6400 · Net book value at 31.03.03-2008 =25600 · Depreciation y/e 31. 2. which necessitates decision regarding depreciation (may be proportionate) · A popular depreciation policy would be: A full year’s charge in the year of acquisition but none in the year of disposal Self Assessment Questions Fill up the blanks with appropriate words: 1. In practice. The functional reliability refers to the ____________________ of the machine. Calculate the profit or loss arising on this disposal.2520 [sale price of Rs.
. The main function of the maintenance department is to monitor and control the condition of machineries and equipments and improve their ____________________. the disposal occurred exactly 3 years after the acquisition. The asset is sold on 1 January 2009 for Rs. acquisition or disposal may occur part way through the accounting year. · Original cost 40000 · Depreciation y/e 31.40000.03.23000. there is a profit on disposal of price of Rs. equipment or service operation.03-2009 =20480 · Thus.2007 =32000 · Depreciation y/e 31.2007 (20%) =8000 · Net book value at 31.

Reliability and availability have become key issues. The graph of the failure pattern. The objective of FMEA ( ) and reliability analysis of the plant and equipment is to ensure to ____________________ of critical assets and achieve the business goals. is shown below. which is called the______________. the rate of failure increases until the equipment succumbs and is characterized by the rapid wear and tear of more and more components until major breakdown happens. may contribute to of the ____________ total breakdown time 10. 5. As per the graph. In the ____________ .. 11. A simple machine having few moving parts may have breakdowns happenings after a large number of maintenance free run time hours. called the ‘Weibull distribution graph’ (after Weibull developed it). Hence the reliability of the total system depends on the _________________ of each of the sub systems. It is also commonly called as ____________________. Newly installed equipment shows high rate incidence of early failures during initial phase of its life. This is the useful period of the machine. As in other types of probabilities. because of its shape. it is important to know the nature and occurrence of failures over a period of time for the equipment in use. 4. The formula used to measure manufacturing reliability (MR) is: MR = ………………………. here too is that the small percentage of around 15-20% defects in equipment. there are three phases in the equipment performance namely a) Infant mortality phase b) Useful performance phase c) _____________________ 6. _________________ of maintenance problems is essential to know as to how serious is the problem for taking quick actions. Manufacturing reliability can be defined as a manufacturing system’s ____________. 8. The failure of any one of the sub system can cause failure of the __________________.3. the failure of any one part may result in the ____________________ . 7. Most equipment that survives infancy stage will continue to perform better with very few failures.
. In the performance phase is the ______________ period of performance with a better reliability. For better maintenance planning and control. but in a complex machine. 9. and manufacture the quality product at the speed required.

anticipated life etc. reliability methodologies. tools and techniques and measures. S = Speed performance ] 12. Therefore it is the duty of the plant maintenance crew to strive to maintain and increase the functional reliability of the production facilities. Mean Time between Failure (MTBF) can be computed. 13. The objective of FMEA ( ) and reliability analysis of the plant and equipment is to ensure to excellence in performance of critical assets and achieve the business goals. Asset life cycle management system.[Where. The reliability theories on equipment have shown that there is a definite performance pattern their lifespan. The replacement analysis becomes more complex due to many technical factors and the qualitative consideration. equipment or service operation. This pattern manifests itself due to rigorous operations during the life span. RCM provides a flow diagram that tells what type of maintenance to be used. 9. analysis. Reliability and availability have become key issues. as evolved by some companies for better results consists of three phases: a) Asset Acquisition Phase: b) Maintenance phase: c) ____________________ 14. by which the system reliability. Manufacturing reliability can be defined as a manufacturing system’s capability to operate to its expected operations. can be assessed. Q = Quality performance. Some important methods or replacement of old and unused machineries are 1) minimum annual cost method 2) by using ____________________ 3) ____________________ method.16 Summary The main function of the maintenance department is to monitor and control the condition of machineries and improve their functional reliability. and manufacture the quality product at the speed required. availability. The functional reliability of facilities to be maintained or improved upon by the maintenance management requires the use of certain concepts. T = Time performance.
. The functional reliability refers to the consistency of the degree of performance of the machine. The purpose of reliability centred maintenance (RCM) is to determine the __________________ in its operating contexts.

there must be equipment replacement plan after considering the cost impact and other technical factors.
. Hence the reliability of the total system depends on the product reliability factors of each of the sub systems. The purpose of reliability centred maintenance (RCM) is to determine the maintenance requirements of any physical assets in its operating contexts. Total productive maintenance (TPM) and failure modes and effects analysis (FMEA) are other maintenance tools used for improving the reliability through proactive maintenance. because of its shape. The graph of the failure pattern. Equipment can be considered as a total system and the failure of any one of the sub system can cause failure of the entire system. · Mean Time between Failure (MTBF) · Mean time between production Loss (MTBPL) · Mean production loss (MPL) Companies should recognize this fact that maintenance of its assets is to be encouraged as the process will provide advantages in enhancing quality initiative.For better maintenance planning and control. shows three phases in the equipment performance namely · Infant mortality phase · Useful performance phase · Ageing phase. increases capacity. There are many ways to measure reliability. as evolved by some companies for better results consists of three phases: a) Asset Acquisition Phase b) Maintenance phase c) Disposal Phase Based on the life cycle analysis. Asset life cycle management system. it is important to know the nature and occurrence of failures over a period of time for the equipment in use. called the ‘Weibull distribution graph’ and known as ‘Bath Tub Curve’. reduces costs and eliminate waste. However the methodology to be used depends on the best alternative within the organizations objectives.

Excellence in performance 4.18 Answers Self Assessment Questions 1.Capital expenditure based on the life cycle and the depreciation either by straight line or reducing method is used for a comprehensive decision by the management. 9) What are the technical and cost factors to be considered while planning replacement of old machineries? 10) Explain briefly the depreciation methods used in capital expenditure on plant and machineries. Why it also called as bathtub curve? What are the three phases in the life span of equipment? 4) Explain briefly how the life of the equipment is depicted by the variability and availability factors in a) Bathtub Curve and MTBF. Ageing phase
.17 Terminal Questions 1) Define functional reliability? 2) What are the maintenance management concepts. methodology used for maintaining the functional reliability? 3) Explain briefly the ‘Weibull distribution curve. 9. Consistency of the degree of performance 3. b) Breakdown time distribution: and c) Reliability and Variability of the Equipments 5) What are maintenance performance index? How they help in measuring maintenance efforts? 6) There are many ways of measuring reliability and availability. How this helps in replacement plans? 9. Bath Tub Curve 5. Explain few of them? 7) What are the factors considered in measurement of maintenance measurements? How they are evaluated? Briefly explain the three phases of asset life cycle management. Functional reliability 2.

thus leading to breakdowns and production losses. repairing. High tech preventive maintenance routines are performed by experts at frequent intervals and machines are continually upgraded and modified for closer tolerances. to keep a machine. The Japanese have virtually eliminated machine breakdowns by applying Total Productive Maintenance (TPM) techniques to their
. Health.Development Management Education & Training Safety. a facility. Maintenance covers all those functions such as monitoring.1 Introduction Manufacturers invest huge capital on productive machines and equipments for production of the desired products. adjusting.16 Summary 10.18 Answers 10.13 Relevance of TPM to TQM framework 10. This will increase the life of the machines and they perform better during their entire life span. but they often neglect the very important function of complete maintenance. material handling equipment and other transport vehicles in proper working conditions. Earlier the maintenance management was viewed as a function with a lesser status compared to manufacturing and its role was restricted to one of carrying out breakdown repair when a machine breaks down. faster set ups and fewer adjustments. machine failures cannot be tolerated. a more sophisticated well managed preventive – maintenance type programs such as TPM or Reliability centred maintenance (RCM) has warranted. Because JIT [Just-inTime] production lines operate very close to capacity in every process. etc.15 Role of TPM in WC-production 10. Environment TPM in offices 10. But with the enlarged scope of maintenance functions when very high cost state of art machineries and equipments are used for higher productivity. inspecting. cleaning.17 Terminal Questions 10. Equipment maintenance is basic to competitive manufacturing.14 Benefits of TPM 10.

2 Total Productive Maintenance [TPM] TPM had its genesis in the Japanese car industry in 1970’s. Here the new quality approach of “prevention at source” was translated to the maintenance environment through the concept of TPM. minimising costs and continuously improving processes for manufacturing. consensus building and continuous improvement. 10.3 Goals · Prevention of equipment deterioration · Maintain the equipment in optimal condition · Establishing basic equipment conditions · Operator is competent to operate machine/ equipment · Elimination of quality defects · Elimination of equipment failure · Elimination of cost losses
. TPM is defined as the means to achieve high level of productivity. 10. Reliability and TPM principles call for avoiding crisis. It first evolved in Nippon Denso a major supplier of the Toyota car company. maximising capacity.machines. Objectives: After studying this unit you will be able to: · Outline the features of TPM · Explain the types of losses related to maintenance · List and explain the steps involved in TPM · Comment on the methods of TPM propounded by experts on Quality. TPM is a well defined and organised maintenance program which places a high value on team work. Machines are cleaned and lubricated frequently by the operators who run those machines. relying on team work. efficiency and effectiveness with zero loss concepts through total participation of all employees with self managing abilities in practices. to achieve total customer satisfaction.

waste and accident-free operations] in all the resources over the entire life cycle of a production system through team work and by overlapping small group activities.10. · Boosting morale of employees. · Maximise asset and equipment effectiveness through OEE [overall equipment effectiveness] and OPE. · Restoring equipment to a like-new condition · Improve maintenance efficiency and effectiveness · On job training of the labour to improve their job skills · To have a sound equipment maintenance management · Effective use of preventive and predictive maintenance technology · Achieve TPM with active participation & involvement in all levels · “Value Added” activity that the equipment is contributing to your products. · Increase plant efficiency. but spreads across as a company-wide culture. · Producing products for customer satisfaction in quality. cost. reduction in equipment life cycle cost. defect.
. ensuring total effectiveness of the plant for higher quality and lesser downtime. · Achieve manufacturing excellence. · Reduction in manufacturing costs. losses.4 Objectives of TPM The principle objectives of TPM are: · Eliminate all breakdowns of machines and equipment to ensure trouble free continuous production. 10. delivery and services.5 TPM-Its Features TPM no longer confines to the maintenance department. means elimination of micro operational issues · Achieve zero loss Concept – [zero breakdown. · To achieve higher reliability/flexibility of equipment and reduce cost through eliminating wastages.

including housekeeping. TPM paves way for an excellent planning. efficiency. TPM is a means to achieve high level of productivity. · Downtime for setups and adjustments. monitoring and controlling practices through a unique ‘8-Pillars Method’. · Speed losses due to discrepancies between designed and actual speeds · Defect losses due to process defects that cause scrap & quality problems.TPM is a method designed to eliminate the losses caused by break-down of machines and equipments by identifying and attacking all causes of its breakdowns and system down time due to such breakdowns. blockages etc. · Defect losses due to reduced yields in processing TPM includes three main elements: · Regular preventive maintenance. through total participation of all employees with self-managing abilities in practice. · Periodic pre-failure replacement or overhauls and · Intolerance for breakdowns or unsafe conditions. effectiveness with zero loss concept. TPM is one of the most valuable strategies for those who want to be competitive & meet the World Class Competition 10. to achieve total customer satisfaction There are six types of losses found in a manufacturing firm: · Downtime due to equipment failure. · Speed losses due to idling and minor stoppages caused by abnormal operations of censors. organizing. leading to another innovative & modern practice under company-wide maintenance practice of TPM? How this evolution has happened and other related issues are briefly given below a) Breakdown Maintenance / Emergency / Corrective Maintenance: Break – down maintenance or emergency maintenance is a remedial or corrective maintenance practice that is undertaken when equipment fails and require repair on an
.6 Evolution of Maintenance Methods What are the other maintenance methods that are universally practiced by industries.

. firms should build up a level of repair capability in order to get the system back in operation much faster. A good maintenance facility should have the following features: 1.emergency or priority basis to set it right. maintenance costs and resultant delay in supply of products to customers as promised. 10. Preventive maintenance policies and techniques must emphasize on all employees to accept the responsibility for the maintenance and perform all the activities to their capability. Obviously this is not an ideal way of keeping quiet until that breakdown happens. This reduces the frequency of machinery break downs and consequent loss of production Break down of a machine in production line can be costly if it means shutting down the entire plant. There exists a relationship between the maintenance costs and the cost of failures with which the level of maintenance Vis-a-Vis frequency of maintenance could be firmed up.7 Other Related Issues a) Improve Repair Capabilities: For reliability and a sound preventive maintenance practices. A high failure rate known as the infant mortality exists during the initial working of the machine and then settles in. When the distributions curve exhibits a narrow standard deviation. the productive maintenance tries to identify signs of equipment deterioration or imminent failure and to take corrective action before it fails. This promotes employee empowerment and system performance c) Productive maintenance or Predictive maintenance – This is an extended preventive maintenance method that tries to reduce the chances of breakdowns by using modern monitoring and analysis techniques such as computer aided monitoring and forecasting and diagnose the condition of the equipment during operation. servicing and replace parts to ensure that the system does not fail during normal operation. This idling will increase the production cost. Here. to uncover potential problems and to make repairs. the preventive maintenance will be more expensive and incidental if it is other way. A study is made on each machine on the MTBF (mean time between failures) distribution. Failure of equipment or machineries may occur at different phases. Well trained maintenance crew. that results in loss of production due to idling of machinery and labour and reduces system capacity. b) Preventive maintenance Preventive maintenance is the activity that is planned and programmed on a regular basis to inspect the system. especially when mass production or continuous production is planned.

issues are closely related with maintenance and maintainability. firms can reduce inventories. c) Reliability and Maintainability – an overview: Quality is multi – dimensional but reliability is a key component of quality. 5. e) Role of operators in TPM
. Ability to establish a repair plan and priorities. It is the probability that a product will operate adequately for a given period in its intended application. The ability of the equipment for operation is determined by mean time between failure (MTBF) and mean time to repair (MTTR) that is: Availability = MTBF / [MTBF + MTTR] d) Equipment problems and competitiveness: Equipment problems and break downs have a direct affect on production costs. product quality and production schedules. safety hazard. they can improve operator safety and reduce injuries from equipment mal functions. Hence by reducing equipment mal functions and break downs. Malfunctioning of machines cause deterioration and results in inefficiency. because of perceive product quality and the exceptional reliability. At the same time. Ability and authority to do material planning. preventive and repair maintenance. schedule disruptions etc. Further these machines may have possible immediate effects such as variability of output. accidents to operators. idling of both machines and the workers using those machines for their work. Specialists work with cross-functional teams & backup responsibility to handle difficult or unusual problems. Ability to design ways to extend MTBF b) Maintenance responsibilities a) Traditional: Maintenance is a functional support activity & employees rely on specialists for custodial services. Ability to identify the cause of break downs 6. Japanese automobile manufacturers have been highly successful in the US market and could gain a high market share. 3. Adequate resources. Since the reliability is concerned with the elapsed time between failures of a product. This will ultimately shorten the life of machines and cause high repair costs. b) Employee ownership TPM: Front-line associates have first responsibility for maintenance in their work places. 4.2. Reliability considers the performance of a product over time. Reliability is a time based concept of quality.

manufacturer and also the operators 8. 3. 10.1. Maintain work order system to provide data for calculation of MTBF (mean time before failure) and MTTR (mean time to repair) 6.
. Data collected must be complete for proper implementation. Perform basic equipment maintenance by cleaning of machines. Restores deteriorated equipment through improvements / related maintenance 2. B) Perform change over and setup the complete machine. In case the problem is an unknown entity.1 Objectives of OEE: a) It helps see a problem so that it can be fixed. Thorough data analysis.8 Overall Equipment Effectiveness [OEE]-Key Indicator of TPM · OEE is a way of measuring how the six major losses shown below are affecting the equipment or in other words a way of measuring the amount of “Value added” activity that the equipment is contributing to the product. f) Role of maintenance department in TPM process: 1. Improve technical maintenance skills of all maintenance personnel through systematic training and work assessments 4. obtain information before such problems are attacked. Ensure maintenance is treating the root cause of the problem and not symptoms 7. Diagnose and perform repairs for the problems identified. periodic diagnostic tests apart from performing appropriate maintenance system to avoid predicted equipment failure 5.8. thus developing the capability to operate similar equipment / machines 10. Understand the manufacturing process to successfully achieve the above. To identify design weaknesses and improve equipment for error free operations 3. checking functions of the basic machine AND safety devices. C) Reduction of minor stoppages and adjustments on aggregates as well as the complete machine. D) Collect data to track equipment performance and document all the data recorded along with production control chart and work order systems. 2. Implement periodical maintenance system that is planned on the data collected from the machine. replacement of filters lubrication of aggregates. Basic skill levels required by operators include: A) Monitoring and maintaining critical process parameters.

10. 6. Formation of committees and sub committees for a) promotion and steering of TPM. monitoring and reviewing TPM results and raising levels and revising standards 10. f) Office TPM.11.12 Eight Pillars of TPM
. Selection of pilot lines 5. Implementation in each of the identified areas is managed directly by a target area committee with assistance from a TPM program team. This stresses the need to shift focus from equipment to the processes within which it is used. d) Planned maintenance. 10. g) Education and training. Focus on 8 pillars.wide is a major project that requires support from top management. e) Quality maintenance.1 Steps in TPM program 1. Reaching Excellence in TPM program by Promotion. even for new areas of operations. Company commitment 3.11 Implementation of TPM Implementing TPM company. h) Safety and environment committee 4. The main focus on equipment maintenance is for improvement of the overall production system. c) Kaizen. Plant audit and initial assessment 2. b) Jishu Hozen. The TPM program team oversees initial planning and coordination of all TPM efforts though ultimately this responsibility is transferred to the maintenance department.

Examples of such defects are: Crack in the housing leakages. Develop standards and data collection: Create standards for clean up and checking of machines. Improve skill levels and personal growth throughout the company 5. 2. Standards for monitoring key process parameters: To develop methods and standards for routine verification of key process parameters / standards operating conditions. 7. Stabilise. Prevent degradation related failures 3. Repair sources of defect (outside of machines). Cleaning of all the surroundings and using Japanese 5S principles for orderly keeping the parts etc. broken / worn out belt. electrical. Provide spare parts and tools: Here all the spare parts should be leveraged at the point of use after considering the inventory levels. Other steps considering the aspects like a) Cooperation from all production related department. 6. Operators should identify and tag the sources of defects / waste that arisen out of the machine operations. 4. Similarly the orderliness of tool availability and display of visual boards can be maintained. lubrication and mechanical should be clearly understood by all in the production line for quick redressing. In case modification is required for easy inspection / elimination of debris / contamination etc a new aggregate covers may be created 3. team leaders. control or prevent deterioration of production equipment 2. should be followed to achieve effective results
. Improve predictability through data analysis and communication Steps to Implement JH: 1. switch not operating properly etc. establish standards for data collection based on the production control chart and develop standards for easy reference. electronic. Initial cleanup It must be closely aligned with 7S of the company and there must be commitment of both the staff and the management for the house keeping. JH audit. Increase access and ease of inspection and maintenance 4. Here the operator executes routine verification and adjustments 5. Here operator has to apply and ask for 5 why’s. set rules to be followed. quick response. first line supervisor should be trained to understand the basic of the equipment and the functions and the systems working in the machines namely Hydraulic. pneumatic. Train operators on function and troubleshooting: Operators. replace cracked parts or worn out seals etc and repair and setup the machine.1.

Six steps followed by planned maintenance are:
. Step 3: Implementation action plan to sustain and develop further possible improvements. MTTR.2 Pillar-2.12. optimize spare parts location etc. which uses maintenance work cycle activities of preventive/predictive/corrective or breakdown maintenance techniques. It is aimed at having trouble free machines and equipment producing defect free products for total customer satisfaction. Overall Online efficiency (OOE) and Overall Plant efficiency (OPE) 3) Decrease Costs: through controls in inventory and WIP 4) Reduction in customer complaints: reduce total downtime and ensure quick deliver to customers 5) Zero accidents: total safety and all actions to save money. optimize machine set ups. · Planned maintenance policy includes a) achieve and sustain availability of machines. 3) reduce spare parts inventory. All out JH: Repeat the cycle 1 – 6 above of the process of managing and monitoring the TPM.12. These steps are: Step 1: Quick Win Shop floor projects: this is a team based approach targeting specific problem areas and realizing immediate benefits Step 2: Critical analysis: analyze what else needs to be changed to make it fixed and create action plans. 4) Act as required to proceed further to improve upon the system/process. 10. Verify the progress made in TPM efforts in planned versus emergency work. Zero accidents and Zero defects. Here an emphasis is on transferring knowledge and creating self sufficient team for results. 10. Here it is aimed at eliminating all 16 losses in the workplace.8.Kobetsu Kaizen (Focussed Improvements) 1) PDCA Cycle: Kaizen: here maintenance team should 1) Plan each step. 3) Check whether successful or not. 2) optimise maintenance costs. Quick change time reduction. There are three steps that aim at quick but short term process improvements supported by long term organizational change. 2) Do the necessary change. 2) Increase in productivity by improving Overall Equipment efficiency (OEE).3 Pillar: 3: Planned Maintenance [Pm] For Zero Loss · Planned maintenance is a systematic management by maintenance department. MTBF. 4) improve reliability and maintainability of machines.

12. 2) Improvement in MTBF and MTTR. root cause is found and improvement action on the process/design are ensured. Here the customer end defects are known through customer complaints and in-house defects known through the quality control personnel. when a) ease of manufacture. are analysed. Results achieved through this pillar are: 1) Improved customer satisfaction and reduction in future complaints 2) Reduction in defects and improved quality 3) Reduction in inspection time 10. 3) Reduction in spare parts consumption 4) Reduction in oil and power consumption 5) Reduction in repair cost 6) Reduction in number of inspection points etc 10. Here also aim is at defect free product to satisfy the customer.5 Pillar-5-Development Management This refers to the learning process that happens in TPM implementation and during different types of maintenance practices.1) Equipment evaluation and recording of present status 2) Restore deterioration and improve on weak links 3) Builds information management systems 4) Prepare time based information and parts and map out a plan 5) Prepare predictive system plan by introducing diagnostic techniques 6) Evaluation of planned maintenance.12. Benefits from Planned Maintenance 1) Reduction in downtime due to breakdowns. b) policy of
.4 Pillar-4-Quality Maintenance for Zero Defects This is a process for controlling the condition of equipment and its components that affect variability in product quality. Focus is on eliminating non-conformances in a systematic manner.

Point by point safety audit. Unsafe conditions like electrical points. The methodology adopted is for understanding of the present machine structure. 10. c) determination of detailed specifications etc are answered. noise generations and any such unsafe potential areas must be identified and action taken to make them safe. health and hazards. breakdowns attributed to lack of knowledge and skills 2) Reduction in further downtime after gaining the knowledge and skills 3) Reductions achieved after training on the number of defects. skills and techniques through a training environment. Development of management involves four phases.7 Pillar-7: Safety. operating machines without proper training etc. engineers and managers are in a position to fulfil the expanded role to be played in successful implementation of TPM. skilled workers. Here the focus is on improvement of the knowledge. e) initial phase production. goggles etc. unsafe working without wearing gloves. too hot areas. incorporate planned maintenance sheets to eliminate defects. unsafe storage/stacking.12.6 Pillar-6-Trining & Education [Flow Of Controls] Through training and education provides the skill and knowledge apart from the experience that enables operators. whose morale is high and who are eager to work and perform the required functions effectively and independently. a) planning b) implementation. Poka-Yoke etc will all result in getting the following benefits: 1) Reduction in accident 2) Reduction in noise 3) Create excellent house-keeping & a good looking workshop through 5S action 4) Reduction in downtime because of breakdowns etc 5) Saving in energy consumption 6) Reduction in industrial waste
. Health & Environment [Zero Accidents] Here the focus is to create a safe work place and a surrounding areas that is not detrimental to process or procedures. safety guards.development of new technologies. providing safe environment place a vital role. c) design. d) manufacturing. This systematic education and training will result in: 1) Reduction in downtime. reworks etc. Some examples of unsafe acts by employees are 1) use of worn out tools.12. It is aimed to have multi skilled & revitalized employees. The continuous training is on safe working. and design validation 10. safety training and monitoring the improvements through Kaizen.

the following strengthen the view that TPM is relevant to TQM:
. manpower etc b) Q: mistakes in cheques. 2) reduction in repetitive works. Here the whole organization should focus. to follow all the principles and procedures laid out in ‘Seven Pillars of TPM’ and achieve the desired overall improvements for the benefit of the organization.12. accounting. stores. Since achieving total productivity is one of the major objectives of TQM.10. TPM aims at keeping the current plant and equipment at its highest productive level through cooperation of all. 6) reduction in customer complaints.8 Pilar-8-Office Tpm [Raise Levels & Select Other Areas] Office TPM includes analysing processes and procedures towards increased office automation. etc d) D” logistic losses due to delay in support function. payment to suppliers. invoices. Further. PQCDS&M principles in Office TPM: a) P: production output loss due to want of materials. we can infer that total productive maintenance is an extension of TQM philosophy to the maintenance function. marketing and sales outlets with high inventories. 7) reduced man power 8 clean and pleasant work environment and 10) reduction in equipment due to emergency despatches/purchases. 10. in information etc e) S: safety in material handling. It is followed to improve productivity and efficiency in the office administration. It identifies and eliminates losses. 5) reduction in n umber of files.13 Relevance of TPM to TQM Framework Good maintenance is fundamental to a productive manufacturing system. payroll. customer returns etc c) C: buying cost. Benefits accrued because of office TPM are 1) Better utilization of work areas. 3) reduction in administration costs. 4) reduction in inventory carrying costs. other safety practices f) M: number of kaizen activities in office areas with improvements not visible TPM is a long range living program. Therefore the Office TPM addresses the seven major losses namely: 1) processing loss 2) communication loss 3) idle loss 4) set up loss 5) accuracy loss 6) non-value added loss 7) cost loss including areas as procurement. cost of inventory carrying. as a strategy. In TPM the barrier between maintenance & production personnel is removed. bills. cost of logistics.

operators develop a sense of ownership for the machines and give special attention to upkeep the machines for sound.· TQM is aimed at satisfying customer requirements. process reliability and reduces the cost of lost production time. in other words working with a zero sum philosophy. TPM is a value adding activity. Here too the operators take the responsibility of cleaning their machines and work areas. · TPM can have a great impact on the operations decision making process. 4) Benefits can be categorized into two types namely: 1) Direct and 2) Indirect a. In view of the above. defects. 2) TPM increases production capacity. · TPM is continuous improvement activity. since it aims at cost reduction and quality improvements for internal requirements and for customer satisfaction. A comprehensive TPM program aspires to implement process capability and its maintenance. there is a direct link between TPM and TQM and also the relevance of a comprehensive maintenance policy is proved for successful TQM implementation. repairs. by using the principles of 5S. TPM aims at the introduction of new and creative ideas which will optimise quality standards and reduce waste and costs to the organisation concerned. vibration. Housekeeping is another area in JIT production system.14 Benefits of TPM An added benefit is that with the added responsibility of all maintenance activities. This developed by JIPM (Japanese Institution of Plant Maintenance) during late 1960’s combines the American practice of PM with Japanese concept of Total Quality Control [TQC] and Total employee involvement [TEI] 1) TPM aims for greater manufacturing competitiveness through improved effectiveness of machines and equipments. tidy and well organised work area will result in better performance Maintenance is the key to achieve zero loss. 10. Direct benefits:
. Process capacity cannot be made available at the cost of quality. scheduling and control of operations depend to a large extent on process capacity and process capability. zero accidents and zero defects. Clean. The planning. 3) TPM also contributes to improvements in safety. smell etc spot problems before they develop. shortened equipment life and inventory. zero breakdowns. morale and pollution control by involving everyone in the process.

Indirect benefits: a) Higher confidence level among the employees b) Favourable change in the attitude of the operators c) Horizontal deployment of a new concepts in all areas d) The workers get a feeling of owning the machine. the entire process or
. . 4) Delivery: Inventory turnover increased by 150% 5) Morale: Improvement suggestions increased by 105% 6) Safety: Accidents reduced to nil 7) Environment: No pollution created 10. Preventive maintenance requires understanding and maintaining all the physical elements of manufacturing – machine components. Reliable. energy reduced consumption reduced by 20%.15 Role Of TPM In World Class Manufacturing Most of the world class manufacturing firms have implemented JIT systems and TQM philosophy to achieve excellence in manufacturing and to have ability to compete globally. equipment and systems so that they consistently perform at the levels required of them.a) Increase in productivity and overall plant efficiency b) Elimination of customers complaints c) Elimination of accidents d) Achieve goals by working as a team b. maintenance cost reduced by 15 -30%. Therefore if any equipment breaks down. well functioning machines and equipments are a pre requisite for JIT and TQM to be successfully implemented in any manufacturing firm. 1) Productivity: Breakdowns reduced by 85% 2) Quality: Defect rate reduced by 50% 3) Cost: Labour cost reduced by 25%. The following results were reported from a typical firm after implementing TPM.

Here the new quality approach of ………………… was translated to the maintenance environment through the concept of TPM. TQM requires quality at the source which implies that machines must be reliable and well functioning. 3) TPM is defined as the means to achieve high level of productivity. Identify. It first evolved in Nippon Denso a major supplier of the Toyota car company. machinists and operators redesign and reconfigure equipment to make it more reliable. while teams of maintenance staff. to achieve ……………………. 4) GOALS: one among following is not an applicable goal. Improved equipment functioning has a positive impact on product quality.. Preventive maintenance is a stepping stone to a higher level of maintenance referred to as “total productive maintenance” (TPM). material handling equipment and other transport vehicles in proper working conditions. In world class companies quality circles form an important component of TQM. easier to maintain and perform better. Maintenance covers all those functions such as ……………… etc. In world class companies the responsibility for repairs and preventive maintenance is assigned to workers. a facility. The involvement of workers in quality circles provides the opportunity for them (members of quality circles) to study maintenance problems. In TPM operators / workers perform basic equipment repairs and preventive maintenance. This will facilitate implementation of an effective preventive maintenance program which is essential for a JIT system Self Assessment Questions Fill up the blanks with appropriate words in the following statements: 1) Equipment maintenance is basic to competitive manufacturing.production line comes to a halt. efficiency and effectiveness with zero loss concepts through total participation of all employees with self managing abilities in practices. • Prevention of equipment deterioration • Maintain the equipment in optimal condition • Establishing basic equipment conditions • Operator’s incompetency
. to keep a machine. engineers. Preventive maintenance practices reduce the breakdown of machines and will keep them in good working condition. 2) TPM had its genesis in the Japanese car industry in 1970’s.

manpower etc
. ……………. One among the following is not the type of loss considered in maintenance. What is that? • P: production output loss due to want of materials. Health & Environment. 7) Overall Equipment Efficiency-Fill in the other two factors: [OEE] = [Availability x ( ……….) X (…………)] 8 Out of Eight pillars of TPM. Safety. Kobetsu-Kaizen. Identify a) Downtime due to equipment failure.• Elimination of quality defects • Elimination of equipment failure • Elimination of cost losses 5) There are six types of losses found in a manufacturing firm. TPM in Offices. Development Management.. blockages etc. that the equipment is contributing to the product. Education & Training. b) Downtime for setups and adjustments. 9) Autonomous maintenance is a phrase coined by the Japanese institute of plant maintenance (JIPM) to describe the shift towards the machine operators ……………………… 10) PQCDS&M principles in Office TPM: In the list below principle D is missing. Identify them Autonomous Maintenance... ………. d) Habitual absenteism by employees e) Speed losses due to discrepancies between designed and actual speeds f) Defect losses due to process defects that cause scrap & quality problems. g) Defect losses due to reduced yields in processing 6) OEE is a way of measuring how the six major losses shown below are affecting the equipment or in other words a way of measuring the amount of ……………………. c) Speed losses due to idling and minor stoppages caused by abnormal operations of censors. two are missing in the following list.

preventive maintenance. Preventive maintenance is a well planned program which involves inspection to uncover potential problem and make the necessary repairs before any breakdown occurs. and total productive maintenance or reliability centred maintenance. cost of inventory carrying. They applied TPM techniques to visually eliminate machine breakdowns. bills.
. 4) Ability and authority to do material planning. customer returns etc • C: buying cost.16 Summary Japanese firms which implemented JIT production and TQM concepts cannot witness any machine failures that affect quality and delayed production schedules. The frequency of preventive maintenance must be balanced with the cost of equipment failure and keep the total costs of preventive and breakdown maintenance put together at the lowest level possible. cost of logistics. 3) Ability to establish a repair plan and priorities. machines are cleaned and lubricated frequently by the operators themselves who run the machines. 6) Ability to design ways to extend MTBF. Which is the sixth one? 1) Well trained maintenance crew.. In the TPM approach to maintenance management. 3) Reduction in inspection time 12) For the above type of TPM. organization should have the features of 1) Well trained maintenance crew. payroll. etc •? • S: safety in material handling. other safety practices • M: number of kaizen activities in office areas with improvements not visible 11) Results achieved through pillar number Four are: 1) Improved customer satisfaction and reduction in future complaints 2) Reduction in ……………. 4) Ability and authority to do material planning.. For the above type of TPM. 2) Adequate resources.. and ……………. invoices. Only five are listed. 10.• Q: mistakes in cheques. A comprehensive maintenance program consists of breakdown maintenance.2) Adequate resources. stores. organization should have the following six features. 3) Ability to establish a repair plan and priorities. While breakdown maintenance is remedial or corrective maintenance or equipment repair when breakdown occurs. 5) …………………….

product quality and production schedules. repairs. 5. poor quality of outputs. especially with the latest TPM as a final and long range solution.17 Terminal Questions 1. formation of a target committee and program team to oversee initial planning and coordination of all TPM efforts and then transfer the responsibility to the maintenance department. by adopting any of the maintenance systems discussed above. high WIP inventories and so on. Quality circles. Discuss on the guiding features of TPM? 3. decrease in productivity. high repair costs. What is total productive maintenance? Is it different from total preventive maintenance?
. TPM helps to maintain process capability.5) Ability to identify the cause of break downs 6) Ability to design ways to extend MTBF. TPM contributes to improved safety. TPM has great relevance to TQM in improvement of productivity and quality. continuous improvement and has a strong strategic relevance like TQM. an important component of TQM provides the opportunity for workers to study maintenance problems and suggest effective maintenance activities which are essential for JIT systems. Distinguish between breakdown maintenance and preventive maintenance. employee morale and pollution control. stoppage of production. shortened equipment life and inventory. Explain briefly the evolution of maintenance practices leading to TPM. 10. idle time. All these help to improve manufacturing competitiveness of world class companies. defects. Benefits of TPM includes increase in production capacity and process reliability. Implementing TPM company-wide is major project requiring top management support. Reduction in costs of lost production. high standards of quality and reliability. safety hazards. TPM identifies and attacks all causes of malfunctions and eliminates all consequent losses due to breakdowns. which may result in inefficiency of machines. accidents to workers. 4. What are the objectives of TPM? 2. Equipment problems have a direct impact on production costs.

etc 2. safe environment under TPM? 15. inspecting. cleaning. Which are the eight pillars that support TPM in an organization? 11. 16. Explain briefly as to how planned maintenance under Eight pillars of TPM help achieve zero loss? 14. Prevention at source 3. What are the benefits accrued to a firm by practicing TPM? 17. Habitual Absenteeism by employees – [Sl. What is meant by ‘Overall Equipment Effectiveness’? What are its constituents? How the six losses are addressed through OEE? 8.6. Explain briefly the sixteen types of losses that are to be considered for elimination by the maintenance department while planning TPM activities. no-(d)] 5. repairing. What are the constituents of Kobetsu Kaizen i. Operator’s incompetency-[Sl. Focussed Improvements and what steps are used to achieve improvement? 13. Total customer satisfaction. no (d)]
. What are the six zero concept that are to be considered while approaching elimination of 16 Losses? 10. adjusting. Monitoring.e. 4. Discuss the relevance of total productive maintenance to TQM framework. Describe the role of total productive maintenance in world class manufacturing. 10. What are the relative issues that are recognized by maintenance department before attempting introduction of TPM in the plant? 7. What are the unsafe practices and how these are controlled by practicing good and healthy. 9.18 Answers Self Assessment Questions 1. What is ‘Autonomous Maintenance? What are its objectives and steps involved in implementing? 12.